|
CH System Design/Overhaul/Maintenance.
This is a long rambling post for which I apologize, but If I just come
in with some questions there will inevitably be requests for more info so I have tried to include all relevant info in one post. As some of you will be aware I am helping a friend who has inherited a house needing lots of updating. The central heating being one such component. The system was designed and installed by the now deceased owner who helpfully kept lots of notes. There are extensive notes on maintenance/repairs and changes from its installation in 1976 until about 2005, but no record of any work since 2005. I'm sure that in its heyday it was well maintained but that very little will have been done to it in the last ten years. As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. (It might be time to remove all active components and start again - although this would probably be beyond my DIY skills -but at least if I understand the system I can have an intelligent discussion with a professional). Having looked at the DIY FAQ pages what I think I have is an "S Plus Pump Plan" ie exactly what we have here http://wiki.diyfaq.org.uk/index.php/...s:_S_Plus-plan but with the zone valves replaced with pumps and what he called "clack valves" (of which more later). The control system looks like a home brew box of relays and diodes. Perhaps some pictures would help. (control box links lower down) https://www.dropbox.com/s/vgvvcdyxlm...ntrol.jpg?dl=0 https://www.dropbox.com/s/4zrocgzq81...nstrs.jpg?dl=0 Now to my mind the radiators are not getting warm because 1) They are blocked - removal and off site flushing should solve this. 2) The pumps aren't pumping - they are either A) blocked or B) not spinning A) Blocked - I have found info on diy faq about stripping and removal of corrosion products from the impeller (more time consuming but cheaper than a simple swap - time is not an issue). B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. 3) Some other blockage. Now this is where we come to the "clack valves". Or to give them their correct title "Null Flow valves". (Leaflet courtesy of his extensive records) https://www.dropbox.com/s/5qxmapfy1s...valve.jpg?dl=0 There is a record of one of these jamming open causing " the landing radiator getting hot when only the DHW pump was running". It was stripped and rebuilt. I can see from the "S Plan plus pump" schematic that if you replace the zone valves with pumps then when only one pump is running there is nothing to stop back-flow in the other loops. Can these jam shut? I'm afraid google has not been my friend and I can find no reference to "clack valves" in modern heating systems. The only reference to NRV seems to be in relation to those fitted to incoming mains supply pipes. If these are jammed shut I can find no on line replacements. The chances of getting an overhaul kit for these valves today must be just about zero. Also the control box seems to be an aladdins cave of relays and diodes. Failure of one or more of these components is of course a possibility. https://www.dropbox.com/s/zm6ung9y1u...rnals.jpg?dl=0 https://www.dropbox.com/s/ksj3mh8wv7...x_pcb.jpg?dl=0 https://www.dropbox.com/s/sae3oudvgb...iring.jpg?dl=0 As far as I can see the design of the control box necessitates mods to the pump wiring circuit board. https://www.dropbox.com/s/wqdjodrxnh...tions.jpg?dl=0 It has taken me days wading through loads of old notes (note all images are of his notes, I have not created anything new), would this system be bread and butter to a current plumber/heating fitter or would they throw up their hands in horror? In the interests of future maintainability is it time to consider replacing the 3 pumps with one, removing the "clack valves", installing three zone valves, upstairs and downstairs programmable thermostats and doing away with the magic control box box of relays and diodes? (Although this will probably be a job for a professional rather than me) This wont be started until the end of this heating season but any help welcome. -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
Brian Gaff wrote:
Obviously cannot help as not able to see images You're lucky, one of them is blurry enough to give you a migraine! |
CH System Design/Overhaul/Maintenance.
On Tuesday, 9 January 2018 17:38:40 UTC, Chris B wrote:
This is a long rambling post for which I apologize, but If I just come in with some questions there will inevitably be requests for more info so I have tried to include all relevant info in one post. As some of you will be aware I am helping a friend who has inherited a house needing lots of updating. The central heating being one such component. The system was designed and installed by the now deceased owner who helpfully kept lots of notes. There are extensive notes on maintenance/repairs and changes from its installation in 1976 until about 2005, but no record of any work since 2005. I'm sure that in its heyday it was well maintained but that very little will have been done to it in the last ten years. As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. (It might be time to remove all active components and start again - although this would probably be beyond my DIY skills -but at least if I understand the system I can have an intelligent discussion with a professional). Having looked at the DIY FAQ pages what I think I have is an "S Plus Pump Plan" ie exactly what we have here http://wiki.diyfaq.org.uk/index.php/...s:_S_Plus-plan but with the zone valves replaced with pumps and what he called "clack valves" (of which more later). The control system looks like a home brew box of relays and diodes. Perhaps some pictures would help. (control box links lower down) https://www.dropbox.com/s/vgvvcdyxlm...ntrol.jpg?dl=0 https://www.dropbox.com/s/4zrocgzq81...nstrs.jpg?dl=0 Now to my mind the radiators are not getting warm because 1) They are blocked - removal and off site flushing should solve this. 2) The pumps aren't pumping - they are either A) blocked or B) not spinning A) Blocked - I have found info on diy faq about stripping and removal of corrosion products from the impeller (more time consuming but cheaper than a simple swap - time is not an issue). B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. 3) Some other blockage. Now this is where we come to the "clack valves". Or to give them their correct title "Null Flow valves". (Leaflet courtesy of his extensive records) https://www.dropbox.com/s/5qxmapfy1s...valve.jpg?dl=0 There is a record of one of these jamming open causing " the landing radiator getting hot when only the DHW pump was running". It was stripped and rebuilt. I can see from the "S Plan plus pump" schematic that if you replace the zone valves with pumps then when only one pump is running there is nothing to stop back-flow in the other loops. Can these jam shut? I'm afraid google has not been my friend and I can find no reference to "clack valves" in modern heating systems. The only reference to NRV seems to be in relation to those fitted to incoming mains supply pipes. If these are jammed shut I can find no on line replacements. The chances of getting an overhaul kit for these valves today must be just about zero. Also the control box seems to be an aladdins cave of relays and diodes. Failure of one or more of these components is of course a possibility. https://www.dropbox.com/s/zm6ung9y1u...rnals.jpg?dl=0 https://www.dropbox.com/s/ksj3mh8wv7...x_pcb.jpg?dl=0 https://www.dropbox.com/s/sae3oudvgb...iring.jpg?dl=0 As far as I can see the design of the control box necessitates mods to the pump wiring circuit board. https://www.dropbox.com/s/wqdjodrxnh...tions.jpg?dl=0 It has taken me days wading through loads of old notes (note all images are of his notes, I have not created anything new), would this system be bread and butter to a current plumber/heating fitter or would they throw up their hands in horror? In the interests of future maintainability is it time to consider replacing the 3 pumps with one, removing the "clack valves", installing three zone valves, upstairs and downstairs programmable thermostats and doing away with the magic control box box of relays and diodes? (Although this will probably be a job for a professional rather than me) This wont be started until the end of this heating season but any help welcome. I suspect the average plumber would run away in horror. I daresay it worked very well in its day, but once there's no-one around that properly understands it it becomes a beast to deal with. I'd look at the pumps first, as they're prime candidates for failure. A hand on them will tell immediately if they're running. Opening them will tell if the impellers are crudded up or broken. If you're just lost as to what's going on with the controls, you might consider fitting neons so you can see at a glance what's going on. I'd also fit a magnaclean or similar near the boiler intake, 10 years of no maintenance makes sludge a prime candidate. Even if the system is entirely replaced you can re-use this. The filter may clog repeatedly at first, causing symptoms, check it often at first. Doing those should give you a lot more idea what's going on. The valves I guess are just one way check valves to prevent backflow. If they need a clean out you may find no kit needed. That's where I'd start. NT |
CH System Design/Overhaul/Maintenance.
|
CH System Design/Overhaul/Maintenance.
On 09/01/2018 19:22, Andy Burns wrote:
wrote: If you're just lost as to what's going on with the controls, you might consider fitting neons so you can see at a glance what's going on. It seems to have three lamps for the two C/H pumps and the H/W pump. Indeed it does, and they light up as expected when the relevant thermostats call for heat, so I suppose in hindsight that rules out any form of fault with the control box. -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
On 09/01/2018 17:38, Chris B wrote:
This is a long rambling post for which I apologize, but If I just come in with some questions there will inevitably be requests for more info so I have tried to include all relevant info in one post. Good plan ;-) As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. Sounds plausible At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. (It might be time to remove all active components and start again - although this would probably be beyond my DIY skills -but at least if I understand the system I can have an intelligent discussion with a professional). It looks like a well planned and designed system - although a bit non standard compared with typical installs today. Having looked at the DIY FAQ pages what I think I have is an "S Plus Pump Plan" ie exactly what we have here http://wiki.diyfaq.org.uk/index.php/...s:_S_Plus-plan but with the zone valves replaced with pumps and what he called "clack valves" (of which more later). Yup. The control system looks like a home brew box of relays and diodes. Perhaps some pictures would help. (control box links lower down) https://www.dropbox.com/s/vgvvcdyxlm...ntrol.jpg?dl=0 https://www.dropbox.com/s/4zrocgzq81...nstrs.jpg?dl=0 Fairly straight forward though - a call for heat in a zone causes it to energise a socket, and that powers the pump. The additional indicator lights being a nice touch to let you "see" the demand. Now to my mind the radiators are not getting warm because 1) They are blocked - removal and off site flushing should solve this. Possible, but odd that they are all blocked - still it could be a common bit of pipework that's blocked. 2) The pumps aren't pumping - they are either A) blocked or B) not spinning A) Blocked - I have found info on diy faq about stripping and removal of corrosion products from the impeller (more time consuming but cheaper than a simple swap - time is not an issue). A good system flushing may also help. (there is an article in the wiki on that) B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. 3) Some other blockage. Now this is where we come to the "clack valves". Or to give them their correct title "Null Flow valves". (Leaflet courtesy of his extensive records) https://www.dropbox.com/s/5qxmapfy1s...valve.jpg?dl=0 There is a record of one of these jamming open causing " the landing radiator getting hot when only the DHW pump was running". It was stripped and rebuilt. I can see from the "S Plan plus pump" schematic that if you replace the zone valves with pumps then when only one pump is running there is nothing to stop back-flow in the other loops. Can these jam shut? No experience of them - but in a badly sludged system anything jamming open or shut could be a distinct possibility! I'm afraid google has not been my friend and I can find no reference to "clack valves" in modern heating systems. The only reference to NRV seems to be in relation to those fitted to incoming mains supply pipes. If these are jammed shut I can find no on line replacements. The chances of getting an overhaul kit for these valves today must be just about zero. You could probably just replace them with a "single" check valve: https://www.screwfix.com/p/single-ch...lve-22mm/61237 You would lose the manual control - but you are unlikely to need that anyway. (failing that you could also use a 2 port zone valve - wired in parallel with the pump - but that's expensive) Also the control box seems to be an aladdins cave of relays and diodes. Failure of one or more of these components is of course a possibility. https://www.dropbox.com/s/zm6ung9y1u...rnals.jpg?dl=0 https://www.dropbox.com/s/ksj3mh8wv7...x_pcb.jpg?dl=0 https://www.dropbox.com/s/sae3oudvgb...iring.jpg?dl=0 As far as I can see the design of the control box necessitates mods to the pump wiring circuit board. https://www.dropbox.com/s/wqdjodrxnh...tions.jpg?dl=0 It has taken me days wading through loads of old notes (note all images are of his notes, I have not created anything new), would this system be bread and butter to a current plumber/heating fitter or would they throw up their hands in horror? One with some experience ought to be able to work it out. Will "different" its not that different. In the interests of future maintainability is it time to consider replacing the 3 pumps with one, removing the "clack valves", installing three zone valves, upstairs and downstairs programmable thermostats and doing away with the magic control box box of relays and diodes? (Although this will probably be a job for a professional rather than me) You could - but I suspect those are not the bits causing the problems. Lack of flow seems like the most likely problem, for one of a couple of possible reasons. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
CH System Design/Overhaul/Maintenance.
On Wednesday, 10 January 2018 01:20:11 UTC, John Rumm wrote:
B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. http://wiki.diyfaq.org.uk/index.php/...ng_pump_repair NT |
CH System Design/Overhaul/Maintenance.
In article ,
Chris B wrote: As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. It's very unlikely the system is blocked to that extent. First thing to do is make sure the pump is working normally, and any electrically controlled valves operating as they should. -- *Beauty is in the eye of the beer holder * Dave Plowman London SW To e-mail, change noise into sound. |
CH System Design/Overhaul/Maintenance.
On Tue, 9 Jan 2018 17:38:34 +0000, Chris B wrote:
Must say what a wonderfully documented self-install! Puts my folder to shame. Nothing wrong with a relay and some diodes (just what is inside any modern, maybe smaller, box). I would try exercising the flow control valves and running the system with the DHW valve manually closed and pump switched off so that only the CH loop should be heating - to see what the boiler flow/return temperatures do. |
CH System Design/Overhaul/Maintenance.
On 10/01/2018 11:35, Geo wrote:
On Tue, 9 Jan 2018 17:38:34 +0000, Chris B wrote: Must say what a wonderfully documented self-install! Puts my folder to shame. Documentation was his strong point, perhaps to excess. Notes being littered with things like "stopping for a cup of tea now" and "perhaps I'll do this after lunch". The only downside is that he has never thrown ****anything**** away so you have to make sure you are looking at the up to date info. It is of course all dated and quite often Timed as well. Fortunately in about 2000 he got a PC and one of his projects was to type up the most current of his hand written notes. (For not only this but everything else to do with the house) -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
On 09/01/2018 17:38, Chris B wrote:
This is a long rambling post for which I apologize, but If I just come in with some questions there will inevitably be requests for more info so I have tried to include all relevant info in one post. As some of you will be aware I am helping a friend who has inherited a house needing lots of updating. The central heating being one such component. The system was designed and installed by the now deceased owner who helpfully kept lots of notes. There are extensive notes on maintenance/repairs and changes from its installation in 1976 until about 2005, but no record of any work since 2005. I'm sure that in its heyday it was well maintained but that very little will have been done to it in the last ten years. As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. (It might be time to remove all active components and start again - although this would probably be beyond my DIY skills -but at least if I understand the system I can have an intelligent discussion with a professional). Having looked at the DIY FAQ pages what I think I have is an "S Plus Pump Plan" ie exactly what we have here http://wiki.diyfaq.org.uk/index.php/...s:_S_Plus-plan but with the zone valves replaced with pumps and what he called "clack valves" (of which more later). The control system looks like a home brew box of relays and diodes. Perhaps some pictures would help. (control box links lower down) https://www.dropbox.com/s/vgvvcdyxlm...ntrol.jpg?dl=0 https://www.dropbox.com/s/4zrocgzq81...nstrs.jpg?dl=0 Now to my mind the radiators are not getting warm because 1) They are blocked - removal and off site flushing should solve this. 2) The pumps aren't pumping - they are either A) blocked or B) not spinning A) Blocked - I have found info on diy faq about stripping and removal of corrosion products from the impeller (more time consuming but cheaper than a simple swap - time is not an issue). B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. 3) Some other blockage. Now this is where we come to the "clack valves". Or to give them their correct title "Null Flow valves". (Leaflet courtesy of his extensive records) https://www.dropbox.com/s/5qxmapfy1s...valve.jpg?dl=0 There is a record of one of these jamming open causing " the landing radiator getting hot when only the DHW pump was running". It was stripped and rebuilt. I can see from the "S Plan plus pump" schematic that if you replace the zone valves with pumps then when only one pump is running there is nothing to stop back-flow in the other loops. Can these jam shut? I'm afraid google has not been my friend and I can find no reference to "clack valves" in modern heating systems. The only reference to NRV seems to be in relation to those fitted to incoming mains supply pipes. If these are jammed shut I can find no on line replacements. The chances of getting an overhaul kit for these valves today must be just about zero. Also the control box seems to be an aladdins cave of relays and diodes. Failure of one or more of these components is of course a possibility. https://www.dropbox.com/s/zm6ung9y1u...rnals.jpg?dl=0 https://www.dropbox.com/s/ksj3mh8wv7...x_pcb.jpg?dl=0 https://www.dropbox.com/s/sae3oudvgb...iring.jpg?dl=0 As far as I can see the design of the control box necessitates mods to the pump wiring circuit board. https://www.dropbox.com/s/wqdjodrxnh...tions.jpg?dl=0 It has taken me days wading through loads of old notes (note all images are of his notes, I have not created anything new), would this system be bread and butter to a current plumber/heating fitter or would they throw up their hands in horror? In the interests of future maintainability is it time to consider replacing the 3 pumps with one, removing the "clack valves", installing three zone valves, upstairs and downstairs programmable thermostats and doing away with the magic control box box of relays and diodes? (Although this will probably be a job for a professional rather than me) This wont be started until the end of this heating season but any help welcome. Well, it certainly isn't a *conventional* S-Plan+ system. That, as you have noted, would have a single pump and one zone valve for each zone (3-in total). It would be wired so that the appropriate zone valve would open whenever its zone was calling for heat, and so that the boiler would fire and the pump would run whenever one or more zones were calling for heat. To achieve the same thing with a pump for each zone, but no valves, requires some relay logic to run the boiler whenever one or more pumps are running. Presumably that's what the control box - with its assortment of diodes and relays - sets out to achieve, but I can't quite get my head around how it does it. [One place where it differs from S-Plan is that it appears to prevent the DHW from heating whenever either or both of the heating zones are calling for heat. If you wanted to convert to S-Plan+ but keep that feature, you'd have to make it non-standard.] The only application I've come across for null-flow valves is to prevent gravity circulation in a pumped system. My first CH system was gravity HW and pumped CH - and the upstairs radiators tended to get warm in the summer when the boiler was just on for the HW and the pump wasn't running. So I inserted what we affectionately called a "foo-foo valve" in the upstairs circuit. This had a flap which could be opened by pump pressure but not by gravity circulation pressure - thus preventing gravity circulation. As others have said, your problem is probably either with the pumps or with silting up of the system. The pumps can be checked fairly easily. It's worth checking that you've got a water path to each side of each radiator by bleeding it with each valve closed in turn until you get a flow of water through the bled hole. A couple more thoughts . . . It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. -- Cheers, Roger ____________ Please reply to Newsgroup. Whilst email address is valid, it is seldom checked. |
CH System Design/Overhaul/Maintenance.
On 10/01/2018 21:02, Roger Mills wrote:
On 09/01/2018 17:38, Chris B wrote: Well, it certainly isn't a *conventional* S-Plan+ system. That, as you have noted, would have a single pump and one zone valve for each zone (3-in total). It would be wired so that the appropriate zone valve would open whenever its zone was calling for heat, and so that the boiler would fire and the pump would run whenever one or more zones were calling for heat. To achieve the same thing with a pump for each zone, but no valves, requires some relay logic to run the boiler whenever one or more pumps are running. Presumably that's what the control box - with its assortment of diodes and relays - sets out to achieve, but I can't quite get my head around how it does it. [One place where it differs from S-Plan is that it appears to prevent the DHW from heating whenever either or both of the heating zones are calling for heat. If you wanted to convert to S-Plan+ but keep that feature, you'd have to make it non-standard.] The only application I've come across for null-flow valves is to prevent gravity circulation in a pumped system. My first CH system was gravity HW and pumped CH - and the upstairs radiators tended to get warm in the summer when the boiler was just on for the HW and the pump wasn't running. So I inserted what we affectionately called a "foo-foo valve" in the upstairs circuit. This had a flap which could be opened by pump pressure but not by gravity circulation pressure - thus preventing gravity circulation. As others have said, your problem is probably either with the pumps or with silting up of the system. The pumps can be checked fairly easily. It's worth checking that you've got a water path to each side of each radiator by bleeding it with each valve closed in turn until you get a flow of water through the bled hole. A couple more thoughts .Â* .Â* . It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Oh yes - several Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. Its unlikely they will have jammed shut as they will not have been touched for several years. Silted up maybe - but I don't think they will be jammed shut. -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
On Wednesday, 10 January 2018 22:35:00 UTC, Chris B wrote:
On 10/01/2018 21:02, Roger Mills wrote: It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Oh yes - several Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. Its unlikely they will have jammed shut as they will not have been touched for several years. Silted up maybe - but I don't think they will be jammed shut. they'd only be shut if someone closed them, but if so one would expect them to have done something about it then. NT |
CH System Design/Overhaul/Maintenance.
wrote:
On Wednesday, 10 January 2018 22:35:00 UTC, Chris B wrote: On 10/01/2018 21:02, Roger Mills wrote: It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. He's got three pumps. IME it can be deceptive if they are mechanically coupled through metal pipes. Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Oh yes - several Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. Its unlikely they will have jammed shut as they will not have been touched for several years. Silted up maybe - but I don't think they will be jammed shut. they'd only be shut if someone closed them, but if so one would expect them to have done something about it then. NT What about these anti-gravity valves? Do they ever get gummed up? -- Roger Hayter |
CH System Design/Overhaul/Maintenance.
On Thursday, 11 January 2018 00:32:57 UTC, Roger Hayter wrote:
tabbypurr wrote: On Wednesday, 10 January 2018 22:35:00 UTC, Chris B wrote: On 10/01/2018 21:02, Roger Mills wrote: It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. He's got three pumps. IME it can be deceptive if they are mechanically coupled through metal pipes. and a control system that makes it trivial to ensure only one is running Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Oh yes - several Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. Its unlikely they will have jammed shut as they will not have been touched for several years. Silted up maybe - but I don't think they will be jammed shut. they'd only be shut if someone closed them, but if so one would expect them to have done something about it then. What about these anti-gravity valves? Do they ever get gummed up? Not something I know about. I can't imagine how they'd be muck-proof, but someone else hopefully knows. NT |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 00:06, wrote:
On Wednesday, 10 January 2018 22:35:00 UTC, Chris B wrote: On 10/01/2018 21:02, Roger Mills wrote: It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. The point is that it gives you access to the shaft, which in many cases will allow you to free a stuck pump. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
CH System Design/Overhaul/Maintenance.
wrote:
On Thursday, 11 January 2018 00:32:57 UTC, Roger Hayter wrote: tabbypurr wrote: On Wednesday, 10 January 2018 22:35:00 UTC, Chris B wrote: On 10/01/2018 21:02, Roger Mills wrote: It's presumably a vented system with a fill & expansion tank in the attic? Could that have run dry (if its ball valve stuck shut) allowing air to enter the heating circuits? Air locks would certainly prevent any decent flow. Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. He's got three pumps. IME it can be deceptive if they are mechanically coupled through metal pipes. and a control system that makes it trivial to ensure only one is running But you'd have to make sure it was working properly by checking the voltages or disconnecting the other pumps and it would be quicker just to take the screw-on cover off. Are there any manual valves - e.g. for balancing the flow in the 3 circuits, or for maintenance purposes? Oh yes - several Gate valves in particular are notorious for jamming shut - even when the spindle appears to turn. Its unlikely they will have jammed shut as they will not have been touched for several years. Silted up maybe - but I don't think they will be jammed shut. they'd only be shut if someone closed them, but if so one would expect them to have done something about it then. What about these anti-gravity valves? Do they ever get gummed up? Not something I know about. I can't imagine how they'd be muck-proof, but someone else hopefully knows. NT -- Roger Hayter |
CH System Design/Overhaul/Maintenance.
On Thursday, 11 January 2018 01:39:46 UTC, Roger Hayter wrote:
tabbypurr wrote: On Thursday, 11 January 2018 00:32:57 UTC, Roger Hayter wrote: tabbypurr wrote: Yes its certainly this type - I have not checked the header tank but will do, along with removing the little silver disk at the end of the pumps to check for rotation as someone else suggested. no point, just put your hand on it or your ear to it. He's got three pumps. IME it can be deceptive if they are mechanically coupled through metal pipes. and a control system that makes it trivial to ensure only one is running But you'd have to make sure it was working properly by checking the voltages or disconnecting the other pumps and it would be quicker just to take the screw-on cover off. all pumps are plugged in. Disconnecting others is trivial. Volt checking them is trivial - in fact AIUI the system already has lamps showing pump voltage. Plugging them into an extension lead is trivial. If there's a problem with a pump then there's a reason to open it. NT |
CH System Design/Overhaul/Maintenance.
On Tuesday, 9 January 2018 17:38:40 UTC, Chris B wrote:
This is a long rambling post for which I apologize, but If I just come in with some questions there will inevitably be requests for more info so I have tried to include all relevant info in one post. As some of you will be aware I am helping a friend who has inherited a house needing lots of updating. The central heating being one such component. The system was designed and installed by the now deceased owner who helpfully kept lots of notes. There are extensive notes on maintenance/repairs and changes from its installation in 1976 until about 2005, but no record of any work since 2005. I'm sure that in its heyday it was well maintained but that very little will have been done to it in the last ten years. As of now the DHW works fine (if somewhat uneconomically) but the room heating system is completely broken, taking several hours to increase the house temperature by a couple of degrees. The radiator temperatures never get much above "slightly above cold", and by feeling the water temperature around the CH pumps and comparing to the DHW pump I am sure that there is very little water circulation round the radiators. At the end of the heating season I intend to drain, remove all radiators, flush, remove pumps and assess but before I even start I want to make sure that I fully understand the system and make sure that I take the right course of action. (It might be time to remove all active components and start again - although this would probably be beyond my DIY skills -but at least if I understand the system I can have an intelligent discussion with a professional). Having looked at the DIY FAQ pages what I think I have is an "S Plus Pump Plan" ie exactly what we have here http://wiki.diyfaq.org.uk/index.php/...s:_S_Plus-plan but with the zone valves replaced with pumps and what he called "clack valves" (of which more later). The control system looks like a home brew box of relays and diodes. Perhaps some pictures would help. (control box links lower down) https://www.dropbox.com/s/vgvvcdyxlm...ntrol.jpg?dl=0 https://www.dropbox.com/s/4zrocgzq81...nstrs.jpg?dl=0 Now to my mind the radiators are not getting warm because 1) They are blocked - removal and off site flushing should solve this. 2) The pumps aren't pumping - they are either A) blocked or B) not spinning A) Blocked - I have found info on diy faq about stripping and removal of corrosion products from the impeller (more time consuming but cheaper than a simple swap - time is not an issue). B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. 3) Some other blockage. Now this is where we come to the "clack valves". Or to give them their correct title "Null Flow valves". (Leaflet courtesy of his extensive records) https://www.dropbox.com/s/5qxmapfy1s...valve.jpg?dl=0 There is a record of one of these jamming open causing " the landing radiator getting hot when only the DHW pump was running". It was stripped and rebuilt. I can see from the "S Plan plus pump" schematic that if you replace the zone valves with pumps then when only one pump is running there is nothing to stop back-flow in the other loops. Can these jam shut? I'm afraid google has not been my friend and I can find no reference to "clack valves" in modern heating systems. The only reference to NRV seems to be in relation to those fitted to incoming mains supply pipes. If these are jammed shut I can find no on line replacements. The chances of getting an overhaul kit for these valves today must be just about zero. Also the control box seems to be an aladdins cave of relays and diodes. Failure of one or more of these components is of course a possibility. https://www.dropbox.com/s/zm6ung9y1u...rnals.jpg?dl=0 https://www.dropbox.com/s/ksj3mh8wv7...x_pcb.jpg?dl=0 https://www.dropbox.com/s/sae3oudvgb...iring.jpg?dl=0 As far as I can see the design of the control box necessitates mods to the pump wiring circuit board. https://www.dropbox.com/s/wqdjodrxnh...tions.jpg?dl=0 It has taken me days wading through loads of old notes (note all images are of his notes, I have not created anything new), would this system be bread and butter to a current plumber/heating fitter or would they throw up their hands in horror? In the interests of future maintainability is it time to consider replacing the 3 pumps with one, removing the "clack valves", installing three zone valves, upstairs and downstairs programmable thermostats and doing away with the magic control box box of relays and diodes? (Although this will probably be a job for a professional rather than me) This wont be started until the end of this heating season but any help welcome. -- Chris B (News) "Clack valve" is an obsolete term for a non-return valve (ie one way flow only). Also called "check valve". It term arises from the noise large one make when the moving part closes. There are several designs of non-return valve, Clack valve is only on of them. It is larger and more costly than others but provides a full bore passage (ie minimum resistance). https://www.pumpsandsystems.com/site...CheckValve.jpg |
CH System Design/Overhaul/Maintenance.
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CH System Design/Overhaul/Maintenance.
On Thursday, 11 January 2018 09:15:44 UTC, Roger Mills wrote:
On 11/01/2018 04:51, tabbypurr wrote: all pumps are plugged in. Disconnecting others is trivial. Volt checking them is trivial - in fact AIUI the system already has lamps showing pump voltage. Plugging them into an extension lead is trivial. If there's a problem with a pump then there's a reason to open it. Your solution certainly verifies that the pump is receiving power and produces a sound. But are you sure that can tell the difference between the sound it makes when rotating as opposed to being stalled? yes. there's no mistaking the difference. Taking the cap off only takes a few seconds. [Even that only shows that the *shaft* is rotating - whereas the impeller may not be, if that has become detached.] Taking the cap off can cause a pump to crash. It has its uses but it's not the best option at this point. NT |
CH System Design/Overhaul/Maintenance.
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CH System Design/Overhaul/Maintenance.
On 10/01/2018 01:20, John Rumm wrote:
On 09/01/2018 17:38, Chris B wrote: Â*Â* B) Not spinning - How do I tell?Â* - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. Gold Blue Peter badge to Mr Rumm. Thank you kind Sir. Both pumps were vibrating slightly to the touch and were drawing power according to one of those plug in power meter thingies. But removal of that little silver screw revealed that neither shaft was actually turning (the water that leaked out was pleasantly clear). A mere touch of the screwdriver on the slotted end and they both leapt into life, with an almost instant change in the temperature of the adjacent pipes and a satisfying amount of gurgling (which soon died away). I can only assume that the long rest last summer had not been good for them (one of the disadvantages of a 3 pump system I suppose, only one pump gets year round use). Radiators now much more sensible temperature (at the top at least), but many have cold spots that one would expect from a sludge build up. One more (and hopefully last - until I drain the system at least) question. Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them https://www.dropbox.com/s/t5613768cj1hezn/Rad1.jpg?dl=0 https://www.dropbox.com/s/z69oos6vi65ear2/Rad2.jpg?dl=0 Thanks to all who have contributed, this has been most helpful. -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
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CH System Design/Overhaul/Maintenance.
Chris B wrote:
On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. Gold Blue Peter badge to Mr Rumm. Thank you kind Sir. Both pumps were vibrating slightly to the touch and were drawing power according to one of those plug in power meter thingies. But removal of that little silver screw revealed that neither shaft was actually turning (the water that leaked out was pleasantly clear). A mere touch of the screwdriver on the slotted end and they both leapt into life, with an almost instant change in the temperature of the adjacent pipes and a satisfying amount of gurgling (which soon died away). I can only assume that the long rest last summer had not been good for them (one of the disadvantages of a 3 pump system I suppose, only one pump gets year round use). Radiators now much more sensible temperature (at the top at least), but many have cold spots that one would expect from a sludge build up. One more (and hopefully last - until I drain the system at least) question. Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them https://www.dropbox.com/s/t5613768cj1hezn/Rad1.jpg?dl=0 https://www.dropbox.com/s/z69oos6vi65ear2/Rad2.jpg?dl=0 Thanks to all who have contributed, this has been most helpful. Strangely, we never gave up our Imperial pipe threads. Indeed, at least some bits of the EU seem to use them. You may need to change the tails screwed into the radiators,[1] but, provided the latter are not too badly corroded, it will be easy to get ones that fit. The correct ones may be provided with the valves, but if not they are cheap. [1] Either because they are obsolescent unions as in your picture or because the compression nuts have the wrong thread. If the latter, new ones are less effort than getting the olives off. -- Roger Hayter |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 18:25, Chris B wrote:
On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: B) Not spinning - How do I tell? - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. Gold Blue Peter badge to Mr Rumm. Thank you kind Sir. Both pumps were I shall wear it to bed ;-) vibrating slightly to the touch and were drawing power according to one of those plug in power meter thingies. But removal of that little silver screw revealed that neither shaft was actually turning (the water that leaked out was pleasantly clear). A mere touch of the screwdriver on the slotted end and they both leapt into life, with an almost instant change in the temperature of the adjacent pipes and a satisfying amount of gurgling (which soon died away). Sounds like a quick bleeding might be in order... I can only assume that the long rest last summer had not been good for them (one of the disadvantages of a 3 pump system I suppose, only one pump gets year round use). Yup... Radiators now much more sensible temperature (at the top at least), but many have cold spots that one would expect from a sludge build up. One more (and hopefully last - until I drain the system at least) question. Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them https://www.dropbox.com/s/t5613768cj1hezn/Rad1.jpg?dl=0 https://www.dropbox.com/s/z69oos6vi65ear2/Rad2.jpg?dl=0 Yup, should be doable - with a couple of possible gottchas ;-) The rad has what looks like a standard 1/2" BSP socket. Into which is currently screwed a tail that matches the valve you have. The tail has a 3/4" BSP nut captive on it, and that tightens it onto the valve (remember that when you come to undo it - you are undoing the nut on the tail from the valve, not the other way around!) Chances are a modern TRV will come with a 15mm compression on both the input and output sides, and a matching tail that is just a 1/2" BSP male taper on one end, and a stub of chrome 15mm pipe on the other. So to make the new valve fit the rad, you will need to remove the existing tail from the rad (using a radiator tail hex key (they look like a large Allen key)) which you stuff up the open end of the tail, and turn. Once removed, brush off any lose rust from the socket. Take the new tail, and wind 10 to 15 turns of PTFE tape on it (or apply other thread sealant), and then thread that into the socket on the rad and do up (pretty) tight (new ones typically need a spanner to tighten on a couple of flats on the outside, rather than the special rad key). Most of that process is illustrated in this article: http://wiki.diyfaq.org.uk/index.php/...s_to_Microbore (you can ignore the bits about the microbore pipe) Next turn your attention to the pipe feeding the valve. That does not look quite like the traditional compression fitting connecting the pipe to the valve - it might be there is some kind of threaded adaptor in there. I suspect that the valve you have actually has a female BSP socket on the bottom of it. You may get lucky and find that: * undoing the very bottom nut will allow the old valve to come off, * you will be left with an olive captive on the pipe and not too much pipe protruding to stop the thing going into the base of the new valve, * the old nut will thread onto the new valve, and finally * and the length of pipe is either right or will move enough to allow the new valve to align with the rad! Then again you might not. You may have to chop off the pipe and extend it[1] to the right height and fit the new valve to that. [1] end feed capillary solder fitting is the neat way, but curpofit (or similar) pushfit can look ok for this application. e.g. Here I needed to fit an "dog leg" adaptation to a rad stem to reach a new metric (and slightly smaller) rad, but wanted to do the final join to the existing pipework while the system was still full of water, so soldering the last bit was out: http://wiki.diyfaq.org.uk/index.php/...tOnRadTail.jpg So I soldered up the pipe offset, fitted the valve to in (and remembered to turn it off!) and stuck the copper pushfit on the bottom, chopped through the pipe with a pipe slice, and put a thumb over the cut end, then quickly stuffed the new bit on with the curpofit on the bottom. Only spilled about a quarter cup full of water. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 18:25, Chris B wrote:
One more (and hopefully last - until I drain the system at least) question. Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them https://www.dropbox.com/s/t5613768cj1hezn/Rad1.jpg?dl=0 https://www.dropbox.com/s/z69oos6vi65ear2/Rad2.jpg?dl=0 Yes, it shouldn't be too difficult. Modern TRVs usually have: - a plain tail (15mm in diameter) with a 1/2" BSP male thread at one end to screw into the radiator - 15mm compression joints on both ends of the valve - one connecting to the tail and the other to the external pipework. The current valve has a tail with a union rather than a plain one, so this tail will have to be removed (likely to have an internal hex socket for an Allen key) and replaced by the tail which comes with the TRV. Both will have 1/2" BSP threads - so no problem there. You'll need some PTFE tape round the threads, of course. The current connection to the external pipe appears to me to be 1/2" BSP on the valve side, with a 1/2" male iron to 1/2" or 15mm[1] compression joint screwed into it. I would get rid of that, and shorten the external pipe by a couple of inches or so. Then use a short length of new 15mm pipe to connect the TRV to the original pipe. You'll need to clean the paint off where you make the joint - and measure the pipe very carefully to determine its size. If it's metric, a straight 15mm solder coupling would be best. If it's imperial, you can get a special 1/2" to 15mm solder coupling. or if you don't mind the joint being a bit more prominent, you can use a compression coupling - which is more forgiving. A 15mm compression coupling will join 1/2"[2] to 15mm with no problem. [1] depending on whether the pipes are imperial or metric [2] Bear in mind that 1/2" is the nominal bore, so that the OD is actually quite close to 15mm -- Cheers, Roger ____________ Please reply to Newsgroup. Whilst email address is valid, it is seldom checked. |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 19:35, John Rumm wrote:
On 11/01/2018 18:25, Chris B wrote: On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: Much advice snipped So I soldered up the pipe offset, fitted the valve to in (and remembered to turn it off!) and stuck the copper pushfit on the bottom, chopped through the pipe with a pipe slice, and put a thumb over the cut end, then quickly stuffed the new bit on with the curpofit on the bottom. Only spilled about a quarter cup full of water. Thanks very much to you and Roger Mills for the tips. Both Posts saved until I start the job in the spring. You have given me the confidence to have a go at it (I have done some plumbing before but it has usually involved removal and replacement of like with like - I am quite happy with taking off the rads flushing them out and putting them back as is.) I have also mastered solder ring couplings. Never been brave enough to try end feed because when you are only using 1 or 2 the price difference is negligible. -- Chris B (News) |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 21:24, Chris B wrote:
On 11/01/2018 19:35, John Rumm wrote: On 11/01/2018 18:25, Chris B wrote: On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: Much advice snipped So I soldered up the pipe offset, fitted the valve to in (and remembered to turn it off!) and stuck the copper pushfit on the bottom, chopped through the pipe with a pipe slice, and put a thumb over the cut end, then quickly stuffed the new bit on with the curpofit on the bottom. Only spilled about a quarter cup full of water. Thanks very much to you and Roger Mills for the tips. Both Posts saved until I start the job in the spring. You have given me the confidence to have a go at it (I have done some plumbing before but it has usually involved removal and replacement of like with like - I am quite happy with taking off the rads flushing them out and putting them back as is.) I have also mastered solder ring couplings. Never been brave enough to try end feed because when you are only using 1 or 2 the price difference is negligible. Yup, solder ring is fine - just slightly more "lumpy". (I tend to use end feed since they are a little bit quicker - less metal to heat so they get to flow temperature quicker. (I keep a small selection of solder ring fittings for when I have to work at arms length etc, and can't spare a hand to hold the solder!) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
CH System Design/Overhaul/Maintenance.
On Thursday, 11 January 2018 15:04:56 UTC, Roger Mills wrote:
On 11/01/2018 13:15, tabbypurr wrote: On Thursday, 11 January 2018 09:15:44 UTC, Roger Mills wrote: On 11/01/2018 04:51, tabbypurr wrote: all pumps are plugged in. Disconnecting others is trivial. Volt checking them is trivial - in fact AIUI the system already has lamps showing pump voltage. Plugging them into an extension lead is trivial. If there's a problem with a pump then there's a reason to open it. Your solution certainly verifies that the pump is receiving power and produces a sound. But are you sure that can tell the difference between the sound it makes when rotating as opposed to being stalled? yes. there's no mistaking the difference. Taking the cap off only takes a few seconds. [Even that only shows that the *shaft* is rotating - whereas the impeller may not be, if that has become detached.] Taking the cap off can cause a pump to crash. It has its uses but it's not the best option at this point. Please define "crash" in this context. make nasty noises & stop turning NT |
CH System Design/Overhaul/Maintenance.
On Thursday, 11 January 2018 18:25:13 UTC, Chris B wrote:
On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: Â*Â* B) Not spinning - How do I tell?Â* - Simple 1:1 replacement may be difficult see below. Not spinning is easy to check... you may be able to do it by feel. However if you unscrew that shiny metal bit in the centre (be ready with a cloth - a small amount of water may spill), that should expose the shaft on the end of the impeller. If its not spinning it will be obvious. The shaft also often has a screwdriver slot, which you can use to manually turn the pump and possibly free it. Gold Blue Peter badge to Mr Rumm. Thank you kind Sir. Both pumps were vibrating slightly to the touch and were drawing power according to one of those plug in power meter thingies. But removal of that little silver screw revealed that neither shaft was actually turning (the water that leaked out was pleasantly clear). A mere touch of the screwdriver on the slotted end and they both leapt into life, with an almost instant change in the temperature of the adjacent pipes and a satisfying amount of gurgling (which soon died away). I can only assume that the long rest last summer had not been good for them (one of the disadvantages of a 3 pump system I suppose, only one pump gets year round use). Radiators now much more sensible temperature (at the top at least), but many have cold spots that one would expect from a sludge build up. One more (and hopefully last - until I drain the system at least) question. Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them https://www.dropbox.com/s/t5613768cj1hezn/Rad1.jpg?dl=0 https://www.dropbox.com/s/z69oos6vi65ear2/Rad2.jpg?dl=0 Thanks to all who have contributed, this has been most helpful. Good news. I suggest the no1 priority is to fit a sludge filter. Despite the name, TRVs don't give thermostatic control. NT |
CH System Design/Overhaul/Maintenance.
Chris B wrote:
On 11/01/2018 19:35, John Rumm wrote: On 11/01/2018 18:25, Chris B wrote: On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: Much advice snipped So I soldered up the pipe offset, fitted the valve to in (and remembered to turn it off!) and stuck the copper pushfit on the bottom, chopped through the pipe with a pipe slice, and put a thumb over the cut end, then quickly stuffed the new bit on with the curpofit on the bottom. Only spilled about a quarter cup full of water. Thanks very much to you and Roger Mills for the tips. Both Posts saved until I start the job in the spring. You have given me the confidence to have a go at it (I have done some plumbing before but it has usually involved removal and replacement of like with like - I am quite happy with taking off the rads flushing them out and putting them back as is.) I have also mastered solder ring couplings. Never been brave enough to try end feed because when you are only using 1 or 2 the price difference is negligible. If it is iimpractical to put the pipe joint(s) out of sight (as it usually is with the job you are talking about) then plain end fed fittings look much less obtrusive. -- Roger Hayter |
CH System Design/Overhaul/Maintenance.
On 11/01/2018 23:36, Roger Hayter wrote:
Chris B wrote: On 11/01/2018 19:35, John Rumm wrote: On 11/01/2018 18:25, Chris B wrote: On 10/01/2018 01:20, John Rumm wrote: On 09/01/2018 17:38, Chris B wrote: Much advice snipped So I soldered up the pipe offset, fitted the valve to in (and remembered to turn it off!) and stuck the copper pushfit on the bottom, chopped through the pipe with a pipe slice, and put a thumb over the cut end, then quickly stuffed the new bit on with the curpofit on the bottom. Only spilled about a quarter cup full of water. Thanks very much to you and Roger Mills for the tips. Both Posts saved until I start the job in the spring. You have given me the confidence to have a go at it (I have done some plumbing before but it has usually involved removal and replacement of like with like - I am quite happy with taking off the rads flushing them out and putting them back as is.) I have also mastered solder ring couplings. Never been brave enough to try end feed because when you are only using 1 or 2 the price difference is negligible. If it is iimpractical to put the pipe joint(s) out of sight (as it usually is with the job you are talking about) then plain end fed fittings look much less obtrusive. In the grand scheme of things, even a compression fitting will "vanish" when you stop looking at it all the time! -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
CH System Design/Overhaul/Maintenance.
On Friday, 12 January 2018 00:27:06 UTC, John Rumm wrote:
On 11/01/2018 23:36, Roger Hayter wrote: If it is iimpractical to put the pipe joint(s) out of sight (as it usually is with the job you are talking about) then plain end fed fittings look much less obtrusive. In the grand scheme of things, even a compression fitting will "vanish" when you stop looking at it all the time! paint it the colour of the wall NT |
CH System Design/Overhaul/Maintenance.
wrote:
Despite the name, TRVs don't give thermostatic control. However, if you shell out for one of the systems using motorised heads and separate programmable thermostats, you can get much better performance. I find that being able to control rooms separately and accurately by time of day works well for me. Chris -- Chris J Dixon Nottingham UK Plant amazing Acers. |
CH System Design/Overhaul/Maintenance.
On Friday, 12 January 2018 08:50:35 UTC, Chris J Dixon wrote:
tabbypurr wrote: Despite the name, TRVs don't give thermostatic control. However, if you shell out for one of the systems using motorised heads and separate programmable thermostats, you can get much better performance. I find that being able to control rooms separately and accurately by time of day works well for me. Chris Those things are surely going to be universal in future. I forget the payback period at current prices, I did look at them at one point. NT |
CH System Design/Overhaul/Maintenance.
tabbypurr wrote:
Chris J Dixon wrote: tabbypurr wrote: Despite the name, TRVs don't give thermostatic control. if you shell out for one of the systems using motorised heads and separate programmable thermostats, you can get much better performance. Those things are surely going to be universal in future. I don't like the idea of a set of batteries in each motorised TRV head; maybe they could be charged from a thermopile strapped to the radiator, or a little turbine in the flow? |
CH System Design/Overhaul/Maintenance.
In article ,
Chris B wrote: Do I stand any realistic chance of fitting a modern TRV to this sort of radiator, or am I likely to suffer imperial/metric incompatibility? The house is currently about 50/50 these and modern finned panel types. There is no real sign of severe corrosion on any of them 1976 is roughly when I installed my system. Pipe sizes and rad threads haven't changed since then. -- *There are two kinds of pedestrians... the quick and the dead. Dave Plowman London SW To e-mail, change noise into sound. |
CH System Design/Overhaul/Maintenance.
In article ,
Chris B wrote: I have also mastered solder ring couplings. Never been brave enough to try end feed because when you are only using 1 or 2 the price difference is negligible. If you have satisfied the conditions for a good soldered joint - clean, enough heat and a decent flux, end feed are no more difficult to use than solder ring. Especially has so many tend to add solder to solder rings types anyway. Well worth buying bulk packs of such things where the unit cost comes down dramatically. Assuming you store them in a sealed container, they won't ever go off. ;-) And if you DIY your plumbing they are bound to be needed sooner or later. -- *IF A PARSLEY FARMER IS SUED, CAN THEY GARNISH HIS WAGES? Dave Plowman London SW To e-mail, change noise into sound. |
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