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#1
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balancing radiators - is my boiler too small?
I'm having difficulting getting the radiators on the 2nd floor of our
house to heat up. My efforts have so far involved closing down the LSVs almost completely on the hottest rads (kitchen area and ground floor), leaving the LSVs wide open on the 2nd floor, and somewhere in between on the 1st floor. On balancing radiators, the FAQ says... "The important thing is that the return water coming out of each radiator is good and hot. If it's only warm you need to open its Lock Shield Valve (LSV) some more, or if it's already wide open you have to close the LSVs on the hottest radiators instead." The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Thanks, Simon. |
#2
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"Simon Langford" wrote in message om... I'm having difficulting getting the radiators on the 2nd floor of our house to heat up. My efforts have so far involved closing down the LSVs almost completely on the hottest rads (kitchen area and ground floor), leaving the LSVs wide open on the 2nd floor, and somewhere in between on the 1st floor. On balancing radiators, the FAQ says... "The important thing is that the return water coming out of each radiator is good and hot. If it's only warm you need to open its Lock Shield Valve (LSV) some more, or if it's already wide open you have to close the LSVs on the hottest radiators instead." The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Are the pipes large enough? Is there too many elbows rather than bends? The pump may be too small or not on the highest setting. How large is boiler? Size of house, etc? |
#3
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In article ,
Simon Langford wrote: The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? The size of the boiler makes no difference to the water circulation. If you aren't getting even temperatures across all the rads, then this is the problem. -- *Don't squat with your spurs on * Dave Plowman London SW To e-mail, change noise into sound. |
#5
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On Wed, 6 Oct 2004 12:24:05 +0100, "IMM" wrote:
"Simon Langford" wrote in message om... I'm having difficulting getting the radiators on the 2nd floor of our house to heat up. My efforts have so far involved closing down the LSVs almost completely on the hottest rads (kitchen area and ground floor), leaving the LSVs wide open on the 2nd floor, and somewhere in between on the 1st floor. On balancing radiators, the FAQ says... "The important thing is that the return water coming out of each radiator is good and hot. If it's only warm you need to open its Lock Shield Valve (LSV) some more, or if it's already wide open you have to close the LSVs on the hottest radiators instead." The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Are the pipes large enough? Is there too many elbows rather than bends? How do you expect the original poster to know the answer to that? Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
#6
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In an earlier contribution to this discussion,
Simon Langford wrote: I'm having difficulting getting the radiators on the 2nd floor of our house to heat up. My efforts have so far involved closing down the LSVs almost completely on the hottest rads (kitchen area and ground floor), leaving the LSVs wide open on the 2nd floor, and somewhere in between on the 1st floor. On balancing radiators, the FAQ says... "The important thing is that the return water coming out of each radiator is good and hot. If it's only warm you need to open its Lock Shield Valve (LSV) some more, or if it's already wide open you have to close the LSVs on the hottest radiators instead." The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Thanks, Simon. Is the boiler running continuously, or is it cycling on and off on its own stat? If the latter, the boiler has spare capacity - you're just not harnessing it fully. The water needs pumping round with a bit more urge - so that you can get water to the 2nd floor radiators without starving the others. Does your pump have a higher speed setting than you are currently using? If so, turn it up. If not, fit a more powerful one. You need to be able to get an adequate flow to all radiators - with a uniform temperature drop - with all the TRVs wide open. Only then should you turn down the TRVs to establish the right comfort level in each room. -- Cheers, Set Square ______ Please reply to newsgroup. Reply address is invalid. |
#7
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"Phil Addison" wrote in message ... On Wed, 6 Oct 2004 12:24:05 +0100, "IMM" wrote: "Simon Langford" wrote in message om... I'm having difficulting getting the radiators on the 2nd floor of our house to heat up. My efforts have so far involved closing down the LSVs almost completely on the hottest rads (kitchen area and ground floor), leaving the LSVs wide open on the 2nd floor, and somewhere in between on the 1st floor. On balancing radiators, the FAQ says... "The important thing is that the return water coming out of each radiator is good and hot. If it's only warm you need to open its Lock Shield Valve (LSV) some more, or if it's already wide open you have to close the LSVs on the hottest radiators instead." The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Are the pipes large enough? Is there too many elbows rather than bends? How do you expect the original poster to know the answer to that? Erm, erm, it's his system. |
#8
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On Wed, 6 Oct 2004 13:56:01 +0100, "IMM" wrote:
"Phil Addison" wrote in message ... Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Are the pipes large enough? Is there too many elbows rather than bends? How do you expect the original poster to know the answer to that? Erm, erm, it's his system. Oh, so now you think that everyone that owns a central heating system is capable of calculating the required pipe sizes. That's rich coming from the one that refers to all diyers as incompetent. And do try to remember to snip, there's a good chap. Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
#9
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On Wed, 06 Oct 2004 04:14:24 -0700, Simon Langford wrote:
There are number of ways forward: 1) If the boiler is fires up and never stops on its own thermostat until it's turned off then it simply is not powerful enough, or there is something very wrong with it. This is possible but less likely than (2). 2) The pump is simply not pushing the water around hard enough. The boiler is working fine, it gets hot and cuts in and out as needed but the water is not moving around well enough for the number of radiators and size of house and size of pipe work in your installation. 3) As (2) but the pump has become very ineffective - I have known pumps to erode away in adverse circumstances. Details of the make and model of boiler would be useful also is the pump in the boiler or is it elsewhere. If the latter then it may well be a two or 3 speed unit and all you have to do is turn it up a notch. -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html |
#10
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In article , Simon Langford wrote:
[snip] The problem is that the 2nd floor rads are still not hot (just warm), and the ground and 1st floor rads now have cool return pipes. If I open up the LSVs so get hot return pipes on the ground floor, then the 2nd floor rads are even less hot. Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? It seems suspicious that it's just the higher radiators that don't get hot. Have you tried bleeding them to check that they're not full of gas? Your central heating has presumably been idle all summer and gas released by corrosion may have collected upstairs. -- Jan |
#11
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Phil Addison wrote in message . ..
Have you actually followed the detailed procedure, or is the above all you have done? I pretty much summed up all that I've done in my first para - i.e. just closed down the LSVs on the hottest (ground floor) rads, hoping that would force some hot water to make its way up to the second floor. I've not done any proper temperature readings (except using my hand!). All of the go/return plumbing is concealed below the flooring, so I cannot tell how the plumbing is routed. There is about a meter of exposed 'main' pipework near the boiler and I guess the external diameter is about 25mm. If you *have* followed the FAQ procedure, it seems that there is some inadequacy in the plumbing design. To track this down, try the following: Turn off the boiler. Open both valves fully on one radiator and close down all the others. Turn boiler back on. If that radiator heats up, repeat for each of the others in turn. I tried that last night - with all the others locked off, my top rads heat up nice and hot. So no blockages, airlocks, etc. The boiler size would only be a problem if it is firing continuously flat out and the radiators are still not getting all equally hot. This does seem to be the case. If that does not help you will need to give us much more details of the system and what it is doing. OK: I have 10 rads on the ground floor (double panels ranging from 50cm to 120cm, and a 200cm single panel), 2 on the first floor and 2 on the second floor. And a chrome towel rail on each floor. The boiler is a Worcester Highflow 400, running off LPG (costs a fortune!). It has an built-in pump which is not speed adjustable. (The manual says "if there is a switch, it will be factory set to maximum and should not be adjusted".) The whole system was brand new about 18 months ago. I had the same problem all last winter (we had to get electric heaters on the top floor!). Surely whoever installed it would have used an adequate size boiler? It's physically much bigger than in my last house -- and that was a 3-storey house too. I wonder whether the problem is that there are so many more rads on the ground floor than on the upper floors? Thanks again, Simon. |
#12
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In article ,
Simon Langford wrote: I wonder whether the problem is that there are so many more rads on the ground floor than on the upper floors? Please go through the balancing procedure described in the FAQ. -- *Never slap a man who's chewing tobacco * Dave Plowman London SW To e-mail, change noise into sound. |
#13
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"Phil Addison" wrote in message ... On Wed, 6 Oct 2004 13:56:01 +0100, "IMM" wrote: "Phil Addison" wrote in message ... Do you think I need a bigger boiler (it's already a pretty big one)? Or would a faster pump help? Are the pipes large enough? Is there too many elbows rather than bends? How do you expect the original poster to know the answer to that? Erm, erm, it's his system. Oh, so now you think that everyone that owns a central heating system is capable of calculating the required pipe sizes. I'm sure he can tell us how much 22mm or 15mm there is. |
#14
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On Thu, 07 Oct 2004 09:36:53 +0100, "Dave Plowman (News)"
wrote: In article , Simon Langford wrote: I wonder whether the problem is that there are so many more rads on the ground floor than on the upper floors? Please go through the balancing procedure described in the FAQ. To be fair, I think the OP has made some steps in that direction. Where he probably needs help is in judging the amount to open up the LSVs on the lower radiators so as not to starve the upper-floor units of heat. I spent some time re-balancing my system a couple of years ago, and was quite surprised that some radiator valves literally only need to be open half a turn (maybe even less), while others needed to be fully open. I didn't use a thermometer, it has to be said. All my radiators have TRVs and I wasn't entirely convinced that you can follow a rigid approach with one valve when at the other end of the radiator there is another working all by itself (and in general they are almost never fully open or closed but constantly adjusting, especially during times when the water is heating up). Even now, some radiators take a little longer than others to warm up, but once the system is fully heated, they are heating about as evenly as I would want. With the vast majority of the OP's radiators on the ground floor, these are the ones that will, in the main, need to be virtually closed off. He does have quite a large load but the boiler is spec'd at 24kW and ought to be able to cope. Likewise, one would hope the boiler designers fitted a suitable size pump integral pump. -- We had a meeting of the minds but yours didn't show up. Mail john rather than nospam... |
#15
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In article ,
John Laird wrote: Please go through the balancing procedure described in the FAQ. To be fair, I think the OP has made some steps in that direction. Where he probably needs help is in judging the amount to open up the LSVs on the lower radiators so as not to starve the upper-floor units of heat. I spent some time re-balancing my system a couple of years ago, and was quite surprised that some radiator valves literally only need to be open half a turn (maybe even less), while others needed to be fully open. It's some time since I've read the FAQ, but isn't this covered in that? Gate valves tend to be very non linear, as opposed to 'tap' types. I didn't use a thermometer, it has to be said. It makes life so much easier. And accurate DVMs that incorporate a temperature probe are cheap these days - and will find more uses than a pipe thermometer. All my radiators have TRVs and I wasn't entirely convinced that you can follow a rigid approach with one valve when at the other end of the radiator there is another working all by itself (and in general they are almost never fully open or closed but constantly adjusting, especially during times when the water is heating up). Even now, some radiators take a little longer than others to warm up, but once the system is fully heated, they are heating about as evenly as I would want. I didn't believe just how important taking time to balance the system properly was - thinking you could just rely on the TRVs. But if you want the house to warm up evenly, it's vital. With the vast majority of the OP's radiators on the ground floor, these are the ones that will, in the main, need to be virtually closed off. Yes. He does have quite a large load but the boiler is spec'd at 24kW and ought to be able to cope. Likewise, one would hope the boiler designers fitted a suitable size pump integral pump. But you need to key down the flow to the rads that are the offenders before worrying about the pump. I've also got a three story house, and my pump is set on minimum (out of three settings). -- *Growing old is inevitable, growing up is optional * Dave Plowman London SW To e-mail, change noise into sound. |
#16
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On 7 Oct 2004 01:26:21 -0700, (Simon Langford)
wrote: Phil Addison wrote in message news: ... Have you actually followed the detailed procedure, or is the above all you have done? I pretty much summed up all that I've done in my first para - i.e. just closed down the LSVs on the hottest (ground floor) rads, hoping that would force some hot water to make its way up to the second floor. I've not done any proper temperature readings (except using my hand!). All of the go/return plumbing is concealed below the flooring, so I cannot tell how the plumbing is routed. There is about a meter of exposed 'main' pipework near the boiler and I guess the external diameter is about 25mm. Has it always been like this? If not, has anything been changed? The 'about 25mm' pipe would either be 22mm or 28mm. What diameter pipes connect to the rads on 2nd floor? If they are skinny (8 or 10mm outside diameter) that is a likely cause, assuming you have properly balanced the system. Even 15mm may be pushing it depending on the length of run and size of the rads. If that is the problem you just might be able to fix it with a more powerful pump, but I wouldn't hold out much hope because if the pipes are too skinny the resistance goes up *very* rapidly as you try to increase the flow rate. The length limits for the runs are really pretty firm, and if exceeded for a given heat load (i.e. radiator size), there is not much alternative to replacing with a larger bore. On the other hand it may be the pipes are OK, but you have one of the other problems I mentioned. If you *have* followed the FAQ procedure, it seems that there is some inadequacy in the plumbing design. To track this down, try the following: Turn off the boiler. Open both valves fully on one radiator and close down all the others. Turn boiler back on. If that radiator heats up, repeat for each of the others in turn. I tried that last night - with all the others locked off, my top rads heat up nice and hot. So no blockages, airlocks, etc. That is a good indication (but only that) that it is just a balancing problem. What you need to do now is *very* slightly crack open the LSV on the downstairs rads to see if they can be got hot without short-circuiting the upstairs loop. It is very important not to open the LSV any more than what gives a hot downstairs radiator. Opening it too much will give no additional benefit to that rad but will cause it to bypass water that should be going to the upper floors. As others have said, you do need to go further than these rough tests and carefully follow the balancing procedure. I have high hopes that that is all that is wrong. A £20 IR thermometer will be a great help to speed up the process which is otherwise very tedious. If you use one, I find a square of black PVC insulating tape stuck to the pipes to be an excellent standard surface from which to measure the temperature. The boiler size would only be a problem if it is firing continuously flat out and the radiators are still not getting all equally hot. This does seem to be the case. Not sure what you mean. So far the rads are not balanced to equally heat, so we cannot yet draw conclusions about the boiler. If that does not help you will need to give us much more details of the system and what it is doing. OK: I have 10 rads on the ground floor (double panels ranging from 50cm to 120cm, and a 200cm single panel), 2 on the first floor and 2 on the second floor. And a chrome towel rail on each floor. Don't forget the towel rails are rads that need balancing too. They can also short-circuit the upper loops. The boiler is a Worcester Highflow 400, running off LPG (costs a fortune!). It has an built-in pump which is not speed adjustable. (The manual says "if there is a switch, it will be factory set to maximum and should not be adjusted".) The whole system was brand new about 18 months ago. I had the same problem all last winter (we had to get electric heaters on the top floor!). Surely whoever installed it would have used an adequate size boiler? It's physically much bigger than in my last house -- and that was a 3-storey house too. I wonder whether the problem is that there are so many more rads on the ground floor than on the upper floors? Sounds like a typical installation where it is all carefully designed by a heating engineer, and then installed by a plumber who has no idea of the importance of balancing. In the groups experience, it seems that virtually the only systems that get balanced are those done by DIYers. It's probably not relevant here, but do you have a decent set of controls? i.e. programmer, room stats, separate control over hot water/central heating, and possibly ability to turn off upstairs/downstairs zones? If you can't get it balanced I should start raising hell with the installer on the basis that it was never working to spec (e.g. to raise rooms by about 24C over outside temp of -3C). This will be aided if you can show charts of room temperature attained vs outside temp. The inside/outside differential is roughly linear, so that if the rad in a room raises it by 5C more than outside on a warm day, that is also what it will do when it is -3C outside. So measure room temps and convert them to what it will be when the outside is -3C and ask the installer what he intends to do about it. These measurements should be with all the room, TRVs and boiler stats turned to max. Is the boiler producing very hot water at its flow, and with cool returning water? If so the heat must be going somewhere, assuming the pump is running!! Is it running? Can you hear it/feel it vibrating? Even so it may still be damaged if any vanes are broken off inside. Take the end cap off and see if the spindle is spinning - only an egg cup of water will come out. Phil Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
#17
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#18
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Thanks for all the replies and help everyone. I think I'm getting
somewhere now. I screwed down all the radiators and towel rails apart from the top floor and ran the boiler for 30 minutes. Sure enough the top floor gets nice and hot. Then I opened up the ground and first floors just a little bit, until some warmth came through. This morning when the heating came on, everything was nice and warm. When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. I'm going to do a proper bleed tonight, and might get myself a digital thermometer as recommended here, to do a proper balance. I'm still pretty sure that the boiler runs flat out (i.e. never cuts out under its own thermostat). It is quite a large house, especially the ground floor which is more than twice the area of the other floors and has some very high ceilings. So maybe a 24KW boiler is only just up to the job? We're about to remove a large radiator from the kitchen and put a wood burning stove in its place, so that might help the boiler load. (I know the kitchen will be colder when the stove's not lit...) Anyway, thanks for all the help. Simon. |
#19
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"Simon Langford" wrote in message om... Thanks for all the replies and help everyone. I think I'm getting somewhere now. I screwed down all the radiators and towel rails apart from the top floor and ran the boiler for 30 minutes. Sure enough the top floor gets nice and hot. Then I opened up the ground and first floors just a little bit, until some warmth came through. This morning when the heating came on, everything was nice and warm. When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. I'm going to do a proper bleed tonight, and might get myself a digital thermometer as recommended here, to do a proper balance. I'm still pretty sure that the boiler runs flat out (i.e. never cuts out under its own thermostat). It is quite a large house, especially the ground floor which is more than twice the area of the other floors and has some very high ceilings. So maybe a 24KW boiler is only just up to the job? We're about to remove a large radiator from the kitchen and put a wood burning stove in its place, so that might help the boiler load. (I know the kitchen will be colder when the stove's not lit...) Anyway, thanks for all the help. Simon. If the boiler is borderline install extra insulation in the loft. Then go around with a silicon gun and get rid of air leaks. |
#20
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In article ,
IMM wrote: If the boiler is borderline install extra insulation in the loft. But only if the boiler is borderline? Then go around with a silicon gun and get rid of air leaks. Absolutely. Seal up all doors windows and airbricks. Haven't had any posts on condensation yet. -- * I like you. You remind me of when I was young and stupid Dave Plowman London SW To e-mail, change noise into sound. |
#21
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On 8 Oct 2004 02:45:03 -0700, (Simon Langford)
wrote: Then I opened up the ground and first floors just a little bit, until some warmth came through. This morning when the heating came on, everything was nice and warm. That's promising. When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. Checkout Ed Sirrets combi/Sealed System FAQ. I'm going to do a proper bleed tonight, and might get myself a digital thermometer as recommended here, to do a proper balance. Having tried the digital multi-meter thermocouple type, and the 'pocket' IR type, I can assure you that the IR type makes the task an order of magnitude easier. I can't find the one I have online anymore, but these two look similar http://www.thermometersdirect.co.uk/item257.htm http://www.mh-1.com/ordering.htm I'm still pretty sure that the boiler runs flat out (i.e. never cuts out under its own thermostat). It is quite a large house, especially the ground floor which is more than twice the area of the other floors and has some very high ceilings. So maybe a 24KW boiler is only just up to the job? A google search for Andy Hall's posts on calculating what the radiator (and hence boiler) sizes should get you the info you need to check it out. With an undersized boiler, accurate balancing is even more important to get the best of what you have. If the boiler is undersized, you probably will end up with a larger temp drop across the rads than the oft quoted 11C; that doesn't matter - what is important is to get the same drop across each rad. We're about to remove a large radiator from the kitchen and put a wood burning stove in its place, so that might help the boiler load. (I know the kitchen will be colder when the stove's not lit...) I have a friend who managed to connect a wood-burning stove (with back boiler) in parallel with his central heating boiler. Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
#22
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In article ,
Phil Addison wrote: Having tried the digital multi-meter thermocouple type, and the 'pocket' IR type, I can assure you that the IR type makes the task an order of magnitude easier. Is it as versatile, though? Maplin do a DVM with temp probe for about a tenner, and a DVM has many other uses too (if you haven't already got one). Can you also the temperature of a domestic oven with the IR type? It's nice to know just how far out a new one actually is... -- *A plateau is a high form of flattery.* Dave Plowman London SW To e-mail, change noise into sound. |
#23
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On 8 Oct 2004 "Dave Plowman (News)" wrote:
In article , IMM wrote: If the boiler is borderline install extra insulation in the loft. But only if the boiler is borderline? Then go around with a silicon gun and get rid of air leaks. Absolutely. Seal up all doors windows and airbricks. Haven't had any posts on condensation yet. Quite right! Make sure that absolutely NO OXYGEN can get into the house. Then light the gas fire or a gas ring if you haven't got a fire. This should burn off the remaining oxygen and generate lots of carbon monoxide. After that you should have no further problems. Unfortunately your next of kin may. -- Richard Porter Mail to username ricp at domain minijem.plus.com "You can't have Windows without pains." |
#24
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When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. If the pressure is 1 bar at ground level, you would EXPECT zero pressure 30 feet up - is it a 3 floor house ? Nick |
#25
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On Fri, 08 Oct 2004 15:21:11 GMT, "nick smith" wrote:
When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. If the pressure is 1 bar at ground level, you would EXPECT zero pressure 30 feet up - is it a 3 floor house ? I've never been quite sure what effect a pump has. If the gauge is "behind" the pump, would a drop from the static pressure be expected ? This drop from 1 bar to nearly zero confused me. It only seems to make sense if the pressure behind the pump *can* fall, in which case what the OP is observing is the pump working harder than before, trying to push the water around the upper floor pipework. (We've exchanged emails and apparently all the inter-floor plumbing is hidden from sight, but I suspect too much has been run in 15mm.) -- The current death rate? One per person, of course. Mail john rather than nospam... |
#26
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"Richard Porter" wrote in message ... On 8 Oct 2004 "Dave Plowman (News)" wrote: In article , IMM wrote: If the boiler is borderline install extra insulation in the loft. But only if the boiler is borderline? Then go around with a silicon gun and get rid of air leaks. Absolutely. Seal up all doors windows and airbricks. Haven't had any posts on condensation yet. Quite right! Make sure that absolutely NO OXYGEN can get into the house. Then light the gas fire or a gas ring if you haven't got a fire. This should burn off the remaining oxygen and generate lots of carbon monoxide. After that you should have no further problems. Unfortunately your next of kin may. Some mothers..... |
#27
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On Fri, 08 Oct 2004 13:38:01 +0100, "Dave Plowman (News)"
wrote: In article , Phil Addison wrote: Having tried the digital multi-meter thermocouple type, and the 'pocket' IR type, I can assure you that the IR type makes the task an order of magnitude easier. Is it as versatile, though? Maplin do a DVM with temp probe for about a tenner, and a DVM has many other uses too (if you haven't already got one). Horses for courses! I have several multi-meters, 1 of which has a thermocouple K-bead on a flying lead , and a maplin food probe. The maplin probe was great for checking the core temp of a joint of beef but when I tried to monitor the meat as it cooked in the oven the lead melted!! Seems the probe was good for 200C or so, but not the flex cable. Doh!! The thermocouple K-bead is accurate in melting ice and boiling water, but its not very good at measuring surface temperature because of the difficulty of getting good thermal and mechanical contact between a tiny near spherical bead and e.g. a grubby 15mm pipe. Before I had my IR that is what I used for balancing with a 'clever' arrangement of rubber and aluminium foil glued into a giant clothes peg. It takes time (lots of it) to rig that onto the pipe of a radiator and then to repeat it on the other side, not to mention backache - all that kneeling down and up again. With the IR, I at first could not get consistent readings, depended exactly which bit of pipe you pointed it at, or at the chrome valve etc. In the end I went for the black emitter idea and stuck a square of black PVC insulating tape to each flow and return pipe just below the valves. With that I get the same reading each time and it is quick. I can run round the house with a clipboard and the IR meter measuring each of the 14 rads in 1/4hr or so. Can you also the temperature of a domestic oven with the IR type? It's nice to know just how far out a new one actually is... Sort of. It measures surface temperatures not air temp so you have to open the oven and point it at the hot walls, and no, it won't work through the glass door. I use the thermocouple K-bead DVM for the oven - it measures the air temp and its flex seems to stand up to the heat, and is thin enough to close the oven door on it. Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
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On Fri, 08 Oct 2004 17:57:37 +0100, John Laird
wrote: On Fri, 08 Oct 2004 15:21:11 GMT, "nick smith" wrote: When I checked the pressure in the system before forcing the heat up to the top floor, it was at 1 bar. After getting the top floor hot it was down to almost zero, so maybe there was a blockage somewhere which has now been shifted. If the pressure is 1 bar at ground level, you would EXPECT zero pressure 30 feet up - is it a 3 floor house ? Surely this is the reading on the boiler gauge? I've never been quite sure what effect a pump has. If the gauge is "behind" the pump, would a drop from the static pressure be expected ? This drop from 1 bar to nearly zero confused me. It only seems to make sense if the pressure behind the pump *can* fall, in which case what the OP is observing is the pump working harder than before, trying to push the water around the upper floor pipework. The static pressure will not be affected by the pump. That only affects the... err... dynamic pressure. Think of a closed circuit consisting of a battery and bulb, and float this from one terminal of another battery. Switching on the bulb doesn't affect the voltage of the other battery. I think its more likely that Simon has lost pressure in the system, perhaps due to bleeding a radiator. Ed Sirret's Sealed Heating System FAQ http://www.makewrite.demon.co.uk/SealedCH.html explains what to do in that case. (We've exchanged emails and apparently all the inter-floor plumbing is hidden from sight, but I suspect too much has been run in 15mm.) Or even 10mm. What diameter pipe emerges to feed the rads? Phil The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/ Remove NOSPAM from address to email me |
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"Richard Porter" wrote in message ... On 8 Oct 2004 "Dave Plowman (News)" wrote: In article , IMM wrote: If the boiler is borderline install extra insulation in the loft. But only if the boiler is borderline? Then go around with a silicon gun and get rid of air leaks. Absolutely. Seal up all doors windows and airbricks. Haven't had any posts on condensation yet. Quite right! Make sure that absolutely NO OXYGEN can get into the house. Then light the gas fire or a gas ring if you haven't got a fire. This should burn off the remaining oxygen and generate lots of carbon monoxide. After that you should have no further problems. Unfortunately your next of kin may. Air leakage may be 30-50% of a typical fuel bill. The Canadians say "built tight ventilate right" Very simple really. |
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Ed Sirett wrote:
1) If the boiler is fires up and never stops on its own thermostat until it's turned off then it simply is not powerful enough, [...] Unless of course it has a modulating burner. -- Andy |
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