Boiler thermostat

[Marymar]

Our central heating guy always sets the boiler at 70 deg C. Max is 80. In really cold weather at 70 deg the house does not reach the temperature required by the thermostat in the living room and consequently the boiler is working non stop. When I asked the guy if I should raise the boiler thermostat he said I would consume more gasoil but I have discovered at 80 the required house temperature is reached and the boiler then works 50 pct of the time to maintain it. Am I right in thinking I use less gasoil to heat the boiler to 80 deg and have the heating working 50 pct of the time than up to 70 deg and have the heating working 100pct of the time?

 

[doitmyself]

You are almost certainly correct, but the only way to prove it is by measuring the consumption, which is easy to do with a gas boiler but not with an oil or LPG.

If the rads have been sized assuming an 80C temperature, then you will not be warm in very cold weather if the flow temperature is only 70C.

It's your house, so set the temperature to whatever is necessary to make you comfortable.