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#1
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Central heating auto bypass valve - setting?
I've balancing my new CH - noticed the flow and return to the boiler
were virtually the same - and the auto bypass valve was set to minimum (0.1 bar = 1m head water IIRC) Closing it down to 0.4 bar has jumped the differential temperature - but I suspect that's too high. The Worcester manual says the pump can deliver 2m head for "21C temperature rise" - nothing else about min flow rates or bypass pressure. Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up. Now this may also suggest I have the lockshields all turned down too low as well (I've opened 1/4 - 3/4 turn as a starting point). |
#2
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Central heating auto bypass valve - setting?
On 11/11/2017 11:44, Tim Watts wrote:
I've balancing my new CH - noticed the flow and return to the boiler were virtually the same - and the auto bypass valve was set to minimum (0.1 bar = 1m head water IIRC) Closing it down to 0.4 bar has jumped the differential temperature - but I suspect that's too high. The Worcester manual says the pump can deliver 2m head for "21C temperature rise" - nothing else about min flow rates or bypass pressure. Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up. Now this may also suggest I have the lockshields all turned down too low as well (I've opened 1/4 - 3/4 turn as a starting point). I have mine set pretty high - based on the assumption that I only want it to do anything when nearly all the TRVs are closed off. A highish differential temperature should keep condensing efficiency up as well. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#3
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Central heating auto bypass valve - setting?
On 11/11/17 16:59, John Rumm wrote:
On 11/11/2017 11:44, Tim Watts wrote: I've balancing my new CH - noticed the flow and return to the boiler were virtually the same - and the auto bypass valve was set to minimum (0.1 bar = 1m head water IIRC) Closing it down to 0.4 bar has jumped the differential temperature - but I suspect that's too high. The Worcester manual says the pump can deliver 2m head for "21C temperature rise" - nothing else about min flow rates or bypass pressure. Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up. Now this may also suggest I have the lockshields all turned down too low as well (I've opened 1/4 - 3/4 turn as a starting point). I have mine set pretty high - based on the assumption that I only want it to do anything when nearly all the TRVs are closed off. A highish differential temperature should keep condensing efficiency up as well. Thanks John. After balancing round 1 (a differential thermometer with 2 pipe clamps certainly makes this quicker!), I have 10-12 across all rads more or less at a flow to rad of 56C (boiler indicates more like 65C internal). Fiddling with the bypass, it seems to start shunting big time at a bit under 0.4bar - so I have set it a smidge over. The plan is now to turn the boiler down to about 55C flow - I have oversized the rads as far as possible with a low flow temperature (and spare in a really cold winter) in mind. Think I'll have to go around one more time in a couple of weeks. Next problem - it's bloody hot upstairs and there are no radiators. But there is about 50-70m of exposed pipework!!! It's been quite tightly run (linked Talon clips) and I cannot get 13mm thick insulation on it. So I'm off to peruse the Internet for either some thinner tube, or I'll have to box it in (and be damned if the flow heats the return a bit). Overall - very happy. I have boiled everyone half to death running it flat out all day. That is very nice - this house has never been this warm |
#4
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Central heating auto bypass valve - setting?
On 11/11/2017 18:31, Tim Watts wrote:
Overall - very happy. I have boiled everyone half to death running it flat out all day. That is very nice - this house has never been this warm Yup its surprising how you notice heat after a long spell without! I grew up in place that did not have CH until I was about 17ish. Getting up on a winter's morning to go to college was a well honed routine - kettle would boil on a time switch. Chuck water in mug left waiting from the night before with coffee and milk in it, and turn on the gas fire in bedroom, before leaping back into bed. Drink coffee and wait for room to become slightly habitable while marvelling at the frozen condensation on the inside of the windows! Then one day I came back up in the evening, and the installers had the new CH fired up, and the place was warm in winter for the first time ever! -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#5
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Central heating auto bypass valve - setting?
On 12/11/17 03:46, John Rumm wrote:
On 11/11/2017 18:31, Tim Watts wrote: Overall - very happy. I have boiled everyone half to death running it flat out all day. That is very nice - this house has never been this warm Yup its surprising how you notice heat after a long spell without! I grew up in place that did not have CH until I was about 17ish. Getting up on a winter's morning to go to college was a well honed routine - kettle would boil on a time switch. Chuck water in mug left waiting from the night before with coffee and milk in it, and turn on the gas fire in bedroom, before leaping back into bed. Drink coffee and wait for room to become slightly habitable while marvelling at the frozen condensation on the inside of the windows! Sounds like my bedroom in Reading, rented off an old polish bloke: 3kW fan heater on timeswitch. Coin meter ran out and I reckon the dT/dt was about 1C/min! Then one day I came back up in the evening, and the installers had the new CH fired up, and the place was warm in winter for the first time ever! |
#6
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Central heating auto bypass valve - setting?
On an aside:
Very pleased that my calculations seem to have borne out. This is my spreadsheet: https://drive.google.com/open?id=1fW...xZKXpMbXX-PTdk I tried to design the biggest radiators in that I could, without taking up excessive space. It was nice to have a clean sheet... PS the rad prices were less via the plumber's discount and over half of the costs were labour, so in the grand scheme of things not too bad. Today, Heat Genius showed the kitchen/dining room (a difficult room to heat - large, 2 big bay windows, no door to side lobby) went from 18.4C at 6am to 20.5C at 7am with a *flow* temperature (external to boiler) of around 55C - that would be the green column H on the sheet, delta-T=30K Sadly the WB boilers do not have a simple weather compensation option (they want you to use their smart programmer to get that and that doesn't work with an external programmer) - so we're pretty much in the land of twiddling the knob each month. However, I'm hoping to reduce that to a simple guide on the boiler - Novemeber - position 4, January - 5 or 6, or something like that... |
#7
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Central heating auto bypass valve - setting?
On 12/11/17 10:55, Tim Watts wrote:
On an aside: On a further aside: I am *very* impressed with the heat output of Ultraheat Tibrook vertical rads: (Ultraheat were recommended here last time I asked): http://www.ultraheat.co.uk/premier-range/tilbrook.html These have been used in a few difficult locations where there was simply no long run of wall available for a normal rad. They're baffled at the bottom forcing water to flow up one half and back down the other half (disadvantage, only bottom entry pipework is allowed) - seems to work. The rest, I used Quinn Compact - a normal typical radiator, but heat outputs for any given configuration are better than competitors. Plus they are made in Wales with British steel so +1 for home production. |
#8
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Central heating auto bypass valve - setting?
Towel rail:
Was warned by plumbers to avoid chrome plated. So went for https://www.screwfix.com/p/a/28451 which is stainless. Looks the same and the miserable amount of heat it throws off (it's purpose is for drying the bath towel) surprisingly seems to keep the bathroom warm (islanded, no external walls) |
#9
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Central heating auto bypass valve - setting?
On Sat, 11 Nov 2017 16:59:53 +0000, John Rumm
wrote: On 11/11/2017 11:44, Tim Watts wrote: I've balancing my new CH - noticed the flow and return to the boiler were virtually the same - and the auto bypass valve was set to minimum (0.1 bar = 1m head water IIRC) Closing it down to 0.4 bar has jumped the differential temperature - but I suspect that's too high. The Worcester manual says the pump can deliver 2m head for "21C temperature rise" - nothing else about min flow rates or bypass pressure. Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up. Now this may also suggest I have the lockshields all turned down too low as well (I've opened 1/4 - 3/4 turn as a starting point). I have mine set pretty high - based on the assumption that I only want it to do anything when nearly all the TRVs are closed off. A highish differential temperature should keep condensing efficiency up as well. Never actually having CH of my own [1] and only dabbling with other peoples when helping them out, I am not up to speed on all the rules re 'balancing' the system, especially on something like a combi / sealed system. I have a question / interest though because I was round my mates the other day when they had the plumbers in because they didn't have any hot water. I had previously been told they had the gas boiler AND immersion on because there were 4 of them showering every morning and the hw would run out otherwise? Anyway, I while back (a couple of years possibly) I had helped them (over the phone) conclude that the immersion had probably gone as it tripped the ELCB in the CU when you turned it on and I thought it had been replaced (but it may have and had gone again)? Anyroadup, the plumbers this time had previously replaced a motorised valve (apparently, a couple of weeks earlier) and they thought it had gone again (faulty) but then found a valve marked up 'Balance, do not touch' that they had been completely turned off and opening it, seemed to have fixed the problem? Now the only time I was aware of a bypass was in the two way motorised valves where when both were off you could potentially short out the boiler so a 15mm pipe was placed in parallel with the HW cylinder and before the mv to ensure there was always a path back to the boiler (or somesuch)? So, my question is 'could it be possible that a 'balance valve' is likely to be (nearly) fully closed and for it to be right' please? I'm asking in case the plumber doing what they did is not a real solution and it will cause issues further down the line? FWIW they have a fairly big HW cylinder and a mix of UF and conventional radiator CH. Cheers, T i m [1] I did actually have the boiler and cylinder fitted here but then my Uncle's coal fired floor standing CH failed so I took my stuff out and fitted it (and some more rads) in his. In fact, because it was a 'low capacity' wall mounted boiler with a copper heat exchanger I also fitted delayed stop relay to the pump and seemed to make the system run very well (and never went wrong once in probably ~20 years). ;-) |
#10
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Central heating auto bypass valve - setting?
On 12/11/17 11:17, T i m wrote:
On Sat, 11 Nov 2017 16:59:53 +0000, John Rumm wrote: On 11/11/2017 11:44, Tim Watts wrote: I've balancing my new CH - noticed the flow and return to the boiler were virtually the same - and the auto bypass valve was set to minimum (0.1 bar = 1m head water IIRC) Closing it down to 0.4 bar has jumped the differential temperature - but I suspect that's too high. The Worcester manual says the pump can deliver 2m head for "21C temperature rise" - nothing else about min flow rates or bypass pressure. Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up. Now this may also suggest I have the lockshields all turned down too low as well (I've opened 1/4 - 3/4 turn as a starting point). I have mine set pretty high - based on the assumption that I only want it to do anything when nearly all the TRVs are closed off. A highish differential temperature should keep condensing efficiency up as well. Never actually having CH of my own [1] and only dabbling with other peoples when helping them out, I am not up to speed on all the rules re 'balancing' the system, especially on something like a combi / sealed system. I have a question / interest though because I was round my mates the other day when they had the plumbers in because they didn't have any hot water. I had previously been told they had the gas boiler AND immersion on because there were 4 of them showering every morning and the hw would run out otherwise? Anyway, I while back (a couple of years possibly) I had helped them (over the phone) conclude that the immersion had probably gone as it tripped the ELCB in the CU when you turned it on and I thought it had been replaced (but it may have and had gone again)? Anyroadup, the plumbers this time had previously replaced a motorised valve (apparently, a couple of weeks earlier) and they thought it had gone again (faulty) but then found a valve marked up 'Balance, do not touch' that they had been completely turned off and opening it, seemed to have fixed the problem? Now the only time I was aware of a bypass was in the two way motorised valves where when both were off you could potentially short out the boiler so a 15mm pipe was placed in parallel with the HW cylinder and before the mv to ensure there was always a path back to the boiler (or somesuch)? So, my question is 'could it be possible that a 'balance valve' is likely to be (nearly) fully closed and for it to be right' please? I'm asking in case the plumber doing what they did is not a real solution and it will cause issues further down the line? It could be a shunt. Normally you use a designated radiator. Or if you don't want to (or don't trust it not to be fiddled with), you could do as I did and put a pressure bypass in, which should only open to protect the boiler pump. FWIW they have a fairly big HW cylinder and a mix of UF and conventional radiator CH. Cheers, T i m [1] I did actually have the boiler and cylinder fitted here but then my Uncle's coal fired floor standing CH failed so I took my stuff out and fitted it (and some more rads) in his. In fact, because it was a 'low capacity' wall mounted boiler with a copper heat exchanger I also fitted delayed stop relay to the pump and seemed to make the system run very well (and never went wrong once in probably ~20 years). ;-) |
#11
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Central heating auto bypass valve - setting?
On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts
wrote: snip Anyroadup, the plumbers this time had previously replaced a motorised valve (apparently, a couple of weeks earlier) and they thought it had gone again (faulty) but then found a valve marked up 'Balance, do not touch' that they had been completely turned off and opening it, seemed to have fixed the problem? Now the only time I was aware of a bypass was in the two way motorised valves where when both were off you could potentially short out the boiler so a 15mm pipe was placed in parallel with the HW cylinder and before the mv to ensure there was always a path back to the boiler (or somesuch)? So, my question is 'could it be possible that a 'balance valve' is likely to be (nearly) fully closed and for it to be right' please? I'm asking in case the plumber doing what they did is not a real solution and it will cause issues further down the line? It could be a shunt. As I describe above (but with some control)? Normally you use a designated radiator. So this would be on all the time, no stat-valve etc? Or if you don't want to (or don't trust it not to be fiddled with), you could do as I did and put a pressure bypass in, which should only open to protect the boiler pump. Ah, that makes more sense and as you eluded to above, less chance of being 'fiddled with'. It will be interesting to see how it all went on Friday (when the plumbers were due back to replace both motorised valves) and whilst they were there the other day I overheard talk of 'one of the motorised valves not being moveable by hand' ... but are they all (as they could have been different makes / designs)? Cheers, T i m |
#12
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Central heating auto bypass valve - setting?
Tim Watts wrote:
On an aside: Very pleased that my calculations seem to have borne out. This is my spreadsheet: https://drive.google.com/open?id=1fW...xZKXpMbXX-PTdk I tried to design the biggest radiators in that I could, without taking up excessive space. It was nice to have a clean sheet... PS the rad prices were less via the plumber's discount and over half of the costs were labour, so in the grand scheme of things not too bad. Today, Heat Genius showed the kitchen/dining room (a difficult room to heat - large, 2 big bay windows, no door to side lobby) went from 18.4C at 6am to 20.5C at 7am with a *flow* temperature (external to boiler) of around 55C - that would be the green column H on the sheet, delta-T=30K Sadly the WB boilers do not have a simple weather compensation option (they want you to use their smart programmer to get that and that doesn't work with an external programmer) - so we're pretty much in the land of twiddling the knob each month. However, I'm hoping to reduce that to a simple guide on the boiler - Novemeber - position 4, January - 5 or 6, or something like that... My WB Greenstar oil boiler has two ways to do weather compensation. Either via a fancy controller or via a separate sensor (plastic case, choc block connector, one thermistor, not even a PCB, 26GBP!) with it's own dedicated terminals on the boiler. Are you sure yours can't do it that way? -- Roger Hayter |
#13
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Central heating auto bypass valve - setting?
On 12/11/17 13:05, T i m wrote:
On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts Normally you use a designated radiator. So this would be on all the time, no stat-valve etc? Yes. And with lockshield valves both ends so normal users don't fiddle. Or if you don't want to (or don't trust it not to be fiddled with), you could do as I did and put a pressure bypass in, which should only open to protect the boiler pump. Ah, that makes more sense and as you eluded to above, less chance of being 'fiddled with'. It will be interesting to see how it all went on Friday (when the plumbers were due back to replace both motorised valves) and whilst they were there the other day I overheard talk of 'one of the motorised valves not being moveable by hand' ... but are they all (as they could have been different makes / designs)? Usually they have an override lever that can be pushed and dropped into a locking slot, for when the motor fails. |
#14
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Central heating auto bypass valve - setting?
On 12/11/17 13:18, Roger Hayter wrote:
Tim Watts wrote: On an aside: Very pleased that my calculations seem to have borne out. This is my spreadsheet: https://drive.google.com/open?id=1fW...xZKXpMbXX-PTdk I tried to design the biggest radiators in that I could, without taking up excessive space. It was nice to have a clean sheet... PS the rad prices were less via the plumber's discount and over half of the costs were labour, so in the grand scheme of things not too bad. Today, Heat Genius showed the kitchen/dining room (a difficult room to heat - large, 2 big bay windows, no door to side lobby) went from 18.4C at 6am to 20.5C at 7am with a *flow* temperature (external to boiler) of around 55C - that would be the green column H on the sheet, delta-T=30K Sadly the WB boilers do not have a simple weather compensation option (they want you to use their smart programmer to get that and that doesn't work with an external programmer) - so we're pretty much in the land of twiddling the knob each month. However, I'm hoping to reduce that to a simple guide on the boiler - Novemeber - position 4, January - 5 or 6, or something like that... My WB Greenstar oil boiler has two ways to do weather compensation. Either via a fancy controller or via a separate sensor (plastic case, choc block connector, one thermistor, not even a PCB, 26GBP!) with it's own dedicated terminals on the boiler. Are you sure yours can't do it that way? No - I read the installer's manual and rang WB tech. They also confirmed that the CDi fancy "Wave" IIRC programmer could not accept an external control input - so not very fancy. |
#15
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Central heating auto bypass valve - setting?
Tim Watts wrote:
On 12/11/17 13:18, Roger Hayter wrote: Tim Watts wrote: On an aside: Very pleased that my calculations seem to have borne out. This is my spreadsheet: https://drive.google.com/open?id=1fW...qxguvxZKXpMbXX -PTdk I tried to design the biggest radiators in that I could, without taking up excessive space. It was nice to have a clean sheet... PS the rad prices were less via the plumber's discount and over half of the costs were labour, so in the grand scheme of things not too bad. Today, Heat Genius showed the kitchen/dining room (a difficult room to heat - large, 2 big bay windows, no door to side lobby) went from 18.4C at 6am to 20.5C at 7am with a *flow* temperature (external to boiler) of around 55C - that would be the green column H on the sheet, delta-T=30K Sadly the WB boilers do not have a simple weather compensation option (they want you to use their smart programmer to get that and that doesn't work with an external programmer) - so we're pretty much in the land of twiddling the knob each month. However, I'm hoping to reduce that to a simple guide on the boiler - Novemeber - position 4, January - 5 or 6, or something like that... My WB Greenstar oil boiler has two ways to do weather compensation. Either via a fancy controller or via a separate sensor (plastic case, choc block connector, one thermistor, not even a PCB, 26GBP!) with it's own dedicated terminals on the boiler. Are you sure yours can't do it that way? No - I read the installer's manual and rang WB tech. They also confirmed that the CDi fancy "Wave" IIRC programmer could not accept an external control input - so not very fancy. That's a shame, I thought that it was one of the big selling points of condensing boilers that you could do this. Not that there appears to be any choice about getting a condensing boiler! I suppose an alternative would be to adjust the flow temperature according to the return temperature, but it probably varies too rapidly for this to work. How does the fancy controller do it without any external informaion? One thing I don't think is common in oil boilers is modulation of heat ouput, It would I think be dfficult to achieve without multiple burners. I don't know how modulation in gas boilers is controlled without external temperature - speed of temperature rise or something? -- Roger Hayter |
#16
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Central heating auto bypass valve - setting?
On Sun, 12 Nov 2017 13:48:20 +0000, Tim Watts
wrote: On 12/11/17 13:05, T i m wrote: On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts Normally you use a designated radiator. So this would be on all the time, no stat-valve etc? Yes. And with lockshield valves both ends so normal users don't fiddle. Check. snip It will be interesting to see how it all went on Friday (when the plumbers were due back to replace both motorised valves) and whilst they were there the other day I overheard talk of 'one of the motorised valves not being moveable by hand' ... but are they all (as they could have been different makes / designs)? Usually they have an override lever that can be pushed and dropped into a locking slot, for when the motor fails. That's what I remember from seeing other peoples systems but I wasn't sure if it was always the case? eg, Can you (could you) 'commonly' get a motorised valve where you can't override it manually? If the answer is 'no', then one that wouldn't move with the lever was very likely to be stuck? Cheers, T i m |
#17
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Central heating auto bypass valve - setting?
On Sun, 12 Nov 2017 13:48:20 +0000, Tim Watts wrote:
On 12/11/17 13:05, T i m wrote: On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts Normally you use a designated radiator. So this would be on all the time, no stat-valve etc? Yes. And with lockshield valves both ends so normal users don't fiddle. Or if you don't want to (or don't trust it not to be fiddled with), you could do as I did and put a pressure bypass in, which should only open to protect the boiler pump. Ah, that makes more sense and as you eluded to above, less chance of being 'fiddled with'. It will be interesting to see how it all went on Friday (when the plumbers were due back to replace both motorised valves) and whilst they were there the other day I overheard talk of 'one of the motorised valves not being moveable by hand' ... but are they all (as they could have been different makes / designs)? Usually they have an override lever that can be pushed and dropped into a locking slot, for when the motor fails. I believe the primary purpose of the locking lever is to force the 3 port diverter valve to keep both ports open to facilitate draining and reduce air locks during refilling operations whilst the system is powered down. It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. -- Johnny B Good |
#18
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Central heating auto bypass valve - setting?
On 12/11/2017 14:02, Roger Hayter wrote:
Tim Watts wrote: No - I read the installer's manual and rang WB tech. They also confirmed that the CDi fancy "Wave" IIRC programmer could not accept an external control input - so not very fancy. That's a shame, I thought that it was one of the big selling points of condensing boilers that you could do this. Some you can easily. Others may require a bit more intervention / invention. You can do stuff with a controlled blending valve on the output of the boiler, that mixes some of the return flow back into the output before its gets reheated. (much as some of the UFH mixers do), but in this case use the external temp to control the mix (when low temps result in less mixing, and hotter effective flow temps) Not that there appears to be any choice about getting a condensing boiler! There are a limited set of cases where you can still legally fit a non condenser. I suppose an alternative would be to adjust the flow temperature according to the return temperature, but it probably varies too rapidly for this to work. How does the fancy controller do it without any external informaion? In the case of the one on mine, via an external temperature sensor. You select a response curve on the programmer based on the heat loss characteristics of the house, and then the programmer picks a flow temperature on that curve based on the current external (and possibly current internal) temperature. One thing I don't think is common in oil boilers is modulation of heat ouput, It would I think be dfficult to achieve without multiple burners. IIUC modern oil boilers do support *some* modulation - but not nearly as wide a range as with gas ones. I don't know how modulation in gas boilers is controlled without external temperature - speed of temperature rise or something? Usually based on the return temperature and the flow set point temperature. As they start to see the return temp start to rise toward the flow temp, they modulate the power down so as not to exceed the flow maximum set temp. If they reach minimum power output and still the return temp is too close to the flow, then they cycle off much like a fixed output boiler would on its stat. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#19
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Central heating auto bypass valve - setting?
On 12/11/2017 15:15, Johnny B Good wrote:
On Sun, 12 Nov 2017 13:48:20 +0000, Tim Watts wrote: On 12/11/17 13:05, T i m wrote: On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts Normally you use a designated radiator. So this would be on all the time, no stat-valve etc? Yes. And with lockshield valves both ends so normal users don't fiddle. Or if you don't want to (or don't trust it not to be fiddled with), you could do as I did and put a pressure bypass in, which should only open to protect the boiler pump. Ah, that makes more sense and as you eluded to above, less chance of being 'fiddled with'. It will be interesting to see how it all went on Friday (when the plumbers were due back to replace both motorised valves) and whilst they were there the other day I overheard talk of 'one of the motorised valves not being moveable by hand' ... but are they all (as they could have been different makes / designs)? Usually they have an override lever that can be pushed and dropped into a locking slot, for when the motor fails. I believe the primary purpose of the locking lever is to force the 3 port diverter valve to keep both ports open to facilitate draining and reduce air locks during refilling operations whilst the system is powered down. Yup. On many it does not activate the microswitch in the same way normal activation would - so does not provide a temporary fix for all ills. It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. Yup two port ones have a similar feature (or at least the Honeywell ones do) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#20
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Central heating auto bypass valve - setting?
On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm
wrote: On 12/11/2017 15:15, Johnny B Good wrote: snip It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. Yup two port ones have a similar feature (or at least the Honeywell ones do) So that's 'the two port ones *can* have a similar feature ...' as that is my question ... are we assured that all makes and models do? The point was that if someone was expecting some form of manual control and thought they saw one, but it didn't move, does that alone guarantee that the valve was faulty / stuck, or could there be some valves that simply couldn't be overridden manually or can only be overridden in one direction or some other conditions(s) etc? I'm not expecting a definitive answer from anyone in particular, just putting the question out there as a definitive answer may suggest my friend is being 'duped' by the plumber ... ;-( Cheers, T i m |
#21
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Central heating auto bypass valve - setting?
On 13/11/2017 15:59, T i m wrote:
On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm wrote: On 12/11/2017 15:15, Johnny B Good wrote: snip It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. Yup two port ones have a similar feature (or at least the Honeywell ones do) So that's 'the two port ones *can* have a similar feature ...' as that is my question ... are we assured that all makes and models do? Not having seen all of them, I can't answer. The point was that if someone was expecting some form of manual control and thought they saw one, but it didn't move, does that alone guarantee that the valve was faulty / stuck, or could there be some valves that simply couldn't be overridden manually or can only be overridden in one direction or some other conditions(s) etc? I would expect that of someone was suggesting the valve were "stuck", they would not be talking about the manual leaver. In these situations is more common to take the motor head right off, and see if the spindle sticking out of the top of the wet bit will turn (with pliers and lubrication etc). If its seized, then replacement of the wet part becomes necessary. I'm not expecting a definitive answer from anyone in particular, just putting the question out there as a definitive answer may suggest my friend is being 'duped' by the plumber ... ;-( -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#22
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Central heating auto bypass valve - setting?
On Mon, 13 Nov 2017 16:46:26 +0000, John Rumm
wrote: On 13/11/2017 15:59, T i m wrote: On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm wrote: On 12/11/2017 15:15, Johnny B Good wrote: snip It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. Yup two port ones have a similar feature (or at least the Honeywell ones do) So that's 'the two port ones *can* have a similar feature ...' as that is my question ... are we assured that all makes and models do? Not having seen all of them, I can't answer. No, quite, it was just the possibility / chance I was talking about. ;-) The point was that if someone was expecting some form of manual control and thought they saw one, but it didn't move, does that alone guarantee that the valve was faulty / stuck, or could there be some valves that simply couldn't be overridden manually or can only be overridden in one direction or some other conditions(s) etc? I would expect that of someone was suggesting the valve were "stuck", they would not be talking about the manual leaver. Ok ... In these situations is more common to take the motor head right off, and see if the spindle sticking out of the top of the wet bit will turn (with pliers and lubrication etc). If its seized, then replacement of the wet part becomes necessary. Ah, so the manual lever isn't actually a manual lever but a manually operated switch to override the timer / controller electrical input? I'm not expecting a definitive answer from anyone in particular, just putting the question out there as a definitive answer may suggest my friend is being 'duped' by the plumber ... ;-( The issues seemed to be (from what I was overhearing from the plumbers) was the possibility that the 'new valve' they had fitted previously (days / weeks before) wasn't working properly but I also heard them saying to the householder that they 'weren't electricians' so I questioned (in my head) just how much they knew about any of it? ;-( Maybe they were just plumbers and what my friends needed was 'Heating engineers'? Time will tell etc. ;-) Cheers, T i m |
#23
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Central heating auto bypass valve - setting?
On Mon, 13 Nov 2017 16:46:26 +0000, John Rumm wrote:
On 13/11/2017 15:59, T i m wrote: On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm wrote: On 12/11/2017 15:15, Johnny B Good wrote: snip It doesn't (or shouldn't) stay in the latched position once the system is powered up and running. I can't say whether this also applies to the two port valves since I only have experience of the 35 yo single 3 port diverter valve (Y or S plan ?) setup used here. Yup two port ones have a similar feature (or at least the Honeywell ones do) So that's 'the two port ones *can* have a similar feature ...' as that is my question ... are we assured that all makes and models do? Not having seen all of them, I can't answer. The point was that if someone was expecting some form of manual control and thought they saw one, but it didn't move, does that alone guarantee that the valve was faulty / stuck, or could there be some valves that simply couldn't be overridden manually or can only be overridden in one direction or some other conditions(s) etc? I would expect that of someone was suggesting the valve were "stuck", they would not be talking about the manual leaver. In these situations is more common to take the motor head right off, and see if the spindle sticking out of the top of the wet bit will turn (with pliers and lubrication etc). If its seized, then replacement of the wet part becomes necessary. When I was looking to fix the problem of the 1st floor radiators warming up when hot water only was called for some two or three years ago, I was initially looking at prices for a complete 3 port Honeywell valve assembly around the 150 quid mark. After a bit of researching, I discovered that I could retain the expensive brass part of the valve body by upgrading the all in one motor/ valve plate to a modern (post 1982!) two part motor and valve plate that would allow any future motor head problems to be fixed without the need for a drain down. I got the valve plate from, I think, my local Plumb Centre[1] and a modern detachable motor head from Tool Station in the end for just under 70 quid all in. One thing that tripped me up was testing the motor head in isolation from the valve plate spindle which revealed a slipping gears problem. It was only *after* experiencing the same "fault" with the replacement from Tool Station that it finally dawned on me that it was the lack of support to the final sector cog normally provided by the valve spindle and the only thing that had been at fault was my testing technique. I felt so bad about returning a fully functioning part as being faulty that I went back to Tool Station, with the second motor unit in hand, just to apologise and explain my mistake to the very accommodating sales member who had dealt with my returned "faulty" motor head just so he could know that there hadn't been anything wrong with the original part in the first place. Compared to Screwfix, the Tool Station counter staff are a joy to deal with so I felt I owed them the courtesy of an apology. Besides which, TS prices are generally lower than SF's prices so yet another reason to show due respect. [1] That was my first port of call because I had hopes of being able to cannibalise the rubber ball to replace the hardened and misshapen one in the original unit which had been the root cause of the problem. Only then did it become clear that I'd need to buy yet another part, a compatible motor head unit before I could complete the repair. I think the valve plate was around 23 quid in all with, to my surprise, Tool Station proving to be the cheapest source of a compatible motor head at a mere 45 quid or so compared to on line sources quoting 65 quid or more. And, whilst I remember, the only other expense involved was the 4 quid spent on the purchase of a 39mm AF open ended chrome vanadium spanner from a second hand tool store my missus had insisted was no longer in business (such insistence resulting in a fruitless search via a 22 mile round trip to the next town's market) to grip the flats of the Honeywell 3 port valve body. Thanks to the upgrade to a modern two piece motor head/ valve plate, a tool I may never use again in anger to repair the central heating system in my lifetime. Thank goodness it was only a mere 4 quid! In all honesty, I think it's more likely to see service as a defensive weapon kept under the bed for use against night time intruders than as a plumbing tool. -- Johnny B Good |
#24
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Central heating auto bypass valve - setting?
On 13/11/2017 22:19, T i m wrote:
On Mon, 13 Nov 2017 16:46:26 +0000, John Rumm wrote: On 13/11/2017 15:59, T i m wrote: On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm wrote: I would expect that of someone was suggesting the valve were "stuck", they would not be talking about the manual leaver. Ok ... In these situations is more common to take the motor head right off, and see if the spindle sticking out of the top of the wet bit will turn (with pliers and lubrication etc). If its seized, then replacement of the wet part becomes necessary. Ah, so the manual lever isn't actually a manual lever but a manually operated switch to override the timer / controller electrical input? No, its a leaver that moves the gearbox mechanism through some of its normal travel - usually enough to move the valve position, but not always enough to bump into the micro switches at the end of the normal motorised travel (and which would be required to fire the boiler with the conventional wiring plan). Its possible for the gearbox or motor to fail, or simply be unable to exert enough force to turn the spindle (either at all, or far enough). In many cases, adding some lubrication to the spindle and working it back and forth with pliers etc will free it enough to work normally after. I'm not expecting a definitive answer from anyone in particular, just putting the question out there as a definitive answer may suggest my friend is being 'duped' by the plumber ... ;-( The issues seemed to be (from what I was overhearing from the plumbers) was the possibility that the 'new valve' they had fitted previously (days / weeks before) wasn't working properly but I also heard them saying to the householder that they 'weren't electricians' so I questioned (in my head) just how much they knew about any of it? ;-( Maybe they were just plumbers and what my friends needed was 'Heating engineers'? Time will tell etc. ;-) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#25
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Central heating auto bypass valve - setting?
On Tue, 14 Nov 2017 02:57:32 +0000, John Rumm
wrote: snip Ah, so the manual lever isn't actually a manual lever but a manually operated switch to override the timer / controller electrical input? No, its a leaver that moves the gearbox mechanism through some of its normal travel - usually enough to move the valve position, but not always enough to bump into the micro switches at the end of the normal motorised travel (and which would be required to fire the boiler with the conventional wiring plan). Ah, thanks. Its possible for the gearbox or motor to fail, or simply be unable to exert enough force to turn the spindle (either at all, or far enough). (We have that now and again with the electric curtains where the track gets damp and the current limit trips before the max travel). In many cases, adding some lubrication to the spindle and working it back and forth with pliers etc will free it enough to work normally after. Yeah, been there and done that with enough stuff over my life, the last being a mates mates motorcycle rear drum brake lever that was actually seizing up. He was going to just spray it with WD40 (that may have worked, especially short time) but I recommended we 'do it properly'. So we removed the rear wheel, stripped the brake drum, cleaned and *re-greased* the lever and replaced the missing O ring / seal. Probably not so easy or appropriate to replicate on a valve full of water though. ;-( Cheers, T i m |
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