If you can't afford to change the boilers then while they are both running get a service contract.
2 condensing boilers
- Thread starter ajrobb
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If you can't afford to change the boilers then while they are both running get a service contract.
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Thought you was banned puller?
You've had more identities than a russian spy on this forum in the last few weeks.
The layout seems to mostly follow the Keston schematic for linking these boilers together;
http://www.keston.co.uk/downloads/support_info/multiple/2xcelsius-v2.pdf
The main difference is that the installer has used a third pump (a secondary pump, the 2 boiler pumps being the primary pumps) for the distribution to the system and has linked the boiler flow and returns together; OTT I suspect.
I don't see the check valves (CVs) so you may get reverse flow through the stand-by boiler when one is firing.
You could isolate one boiler by removing the secondary pump and shutting the IV between the boiler F&R. The boiler pump would then be generating the flow through the boiler and the system, which it is probably capable of doing. It would revert to a standard CH arrangement. You'd need to ensure that ther is flow through the system at all times if there are TRVs fitted. An automatic by-pass valve to replace the IV may be required. You shoukld change-over the boilers occasionally to ensure they both continue to work.
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50,000kwh is about £1500 per year +vat. Rather you than me. The pics of those two c25s are running flat out. Do you keep the whole place heated at 21c throughout the winter?
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It's been installed exactly as keston advise,the manual gate valve is inplace of the auto bypass.
Pipe size on the commons look smaller than recommended,the 35mm is because the heat output when both boilers fire is too great for 22mm and will cause the little heat exchangers to start warping.
Check valves might be hidden under the lagging,but basic layout is reverse return.
Z
3rd pump or system pump as it's being used is there for belts and braces incase the boiler pump isn't upto the job for your system.
Pipe size on the commons look smaller than recommended,the 35mm is because the heat output when both boilers fire is too great for 22mm and will cause the little heat exchangers to start warping.
Check valves might be hidden under the lagging,but basic layout is reverse return.
Z
3rd pump or system pump as it's being used is there for belts and braces incase the boiler pump isn't upto the job for your system.
Hard to tell in the pic but from the lagging, id say the primaries were in 28mm. Blow off looks like 22mm when compared to the condensate. Keston has now changed the design of the exhaust flexi's there like a rubber tube now instead of corrugated. (seem to be better).
Ive also found that the bigger output there boiler the more reliable? Not sure why
Have you tried isolating 1no. boiler to see if it heats your home on its own? If so, i would be looking at purchasing a compensator/optimizer with boiler sequencing.
Save you some money in the long run.
To take some strain off the boilers if the pipework is in 22mm i would be looking at fitting a low loss header and feeding your circuit from that.
HPH Gareth
Ive also found that the bigger output there boiler the more reliable? Not sure why
Have you tried isolating 1no. boiler to see if it heats your home on its own? If so, i would be looking at purchasing a compensator/optimizer with boiler sequencing.
Save you some money in the long run.
To take some strain off the boilers if the pipework is in 22mm i would be looking at fitting a low loss header and feeding your circuit from that.
HPH Gareth
The boilers try that by themselves; when the red fault light starts flashing. No, 25 kW is not enough for cold weather.
But I bet you don't need 50kW.
And I bet you haven't used the Boiler Size Calculator or the Energy Savings Trust Grant Search.
The boiler size calculator says I need 44-48kW. House is 70'x45' chalet bungalow with mostly inaccessible (uninsulated) roof void (over 20kW). I've had cavity wall and loft insulators already.
Have a look here. http://www.heatmiser.co.uk/multiboiler.htm
The plus would be right up your street once you have sorted your insulation out. At the moment you are throwing money away. Could well be saving you up to and over 15% with proper controls.
What sie is the pipework?
The plus would be right up your street once you have sorted your insulation out. At the moment you are throwing money away. Could well be saving you up to and over 15% with proper controls.
What sie is the pipework?
70'x45' is not a bungalow, it's a ranch house!!
You would reduce the roof loss of 22kW to less than 4kW if you insulated the roof with 75mm or more of insulation. The cost of creating access to the roof and laying insulation would probably be recovered in the first year's savings.
No. It's a primary/secondary system. The boiler pumps circulate water in the primary pipework, the secondary circulation is dealt with by the secondary pump. The ABV is not there because it isn't necessary; there will always be primary flow through the boilers even if the secondary circulation is completely stopped by all TRVs being shut.
It's the secondary circulation pump.
Also know as a reverse header.
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