We live in a large 1930s chalet bungalow and our gas consumption is equivalent to 50,000 kWh/annum (was 63,000 before double glazing). When we moved in 7 years ago, we had the heating upgraded and that included two Keston Celcius 25 boilers (25kW condensing system boilers).
Each of the boilers has its own circulating pump but the installers put these on a short circuit "to ensure adequate flow through the boilers" and fitted a third circulating pump to the cylinder and radiators. I have the hall radiator and one radiator in the lounge controlled by the room thermostat (valves always fully open) and TRVs on all the other radiators. I have a Flowmaster Titan 300 litre unvented hot water cylinder.
I have recently read that condensing boilers are more efficient if the mean temperature is kept to a minimum. My concern is that the current arrangement will have high (non-condensing) inlet temperatures.
With the three circulating pumps, I'm wondering how far I can safely close the gate valve on the short circuit?
Each of the boilers has its own circulating pump but the installers put these on a short circuit "to ensure adequate flow through the boilers" and fitted a third circulating pump to the cylinder and radiators. I have the hall radiator and one radiator in the lounge controlled by the room thermostat (valves always fully open) and TRVs on all the other radiators. I have a Flowmaster Titan 300 litre unvented hot water cylinder.
I have recently read that condensing boilers are more efficient if the mean temperature is kept to a minimum. My concern is that the current arrangement will have high (non-condensing) inlet temperatures.
With the three circulating pumps, I'm wondering how far I can safely close the gate valve on the short circuit?