My boiler was set to heat my radiators to 75 degrees. When I had my annual check done, the engineer said it should be set to 60 degrees because that is a more efficient temperature.
What I don’t understand is why is that more efficient in the long run. Yes, the water is heated to a lower temp saving fuel, but now I have to run the heating for longer to get the house warm. Does having the heating on for longer not just cancel about any benefit from lowering the flow temp?
In: 8
The modern “condensing boiler” is more efficient when it can use not just the heat from the combustion of natural gas, but also a condensing process where vapor is converted back into water droplets, which surround the heat exchanger, which in turn extracts the heat and converts it into *additional* heating energy.
When the flow temperature is high, 80C or above, this condensing process doesn’t work so this extra energy that could be harvested is unused and lost. But with a lower flow temperature the boiler can harvest this extra energy.
So running your boiler at a lower temperature will run radiators slightly cooler but for delivering a certain total amount of heat energy into the room, the lower flow temperature will require burning less gas, even though it takes a little longer.
c.f. “If I drive my car flat out in top gear I’ll get there quicker, so how come you’re telling I’ll use less fuel if I drive slower… surely that will take longer so I’ll use more fuel”
Latest Answers