[dowzer]

Our HHS has a timer where you can set the heating to come on or off in 30 minute intervals.

I am wondering (to use a bit less oil) if it is cheaper to eg have the heating on for 1 hour/off for 30 minutes/on for 1 hour etc etc OR will this firing up the burner more often use more oil (or as much as)than if left on constantly?????


Is this a false economy??

[deckingman]

Interesting thought. Presumably you have a room stat as well so that once the room is up to temperature, it will switch the boiler off.

What can happen (and this depends on a number of factors) is that when the room reaches temperature, and the boiler goes off, there is a certain amount of latent heat left in the radiators. So the radiators continue to give off this heat, resulting in a "temperature over swing" before the room start to cool again. So, if this is happening, then "cycling" the boiler as you describe may aleviate this and save a bit of fuel.

On the other hand, it will take longer for the room to reach a given temperature so you may have to start the heating at an earlier time, which would negate any savings. You may also have thermostatic radiator valves which might influence any "over swing" effect.

[robh2002]

If I understand correctly (and I may not) the question boils down to, is it better to have the heating on all the time or on when needed?

Cycling the boiler on and off when heating is required (i.e. the thermostat is calling for heat) will reduce your bills, but also your average room temperature.

The only answer is have the heating on when needed.

Having the heating on the thermostat all the time will increase your bills (and energy use and CO2!). So turn off at night or when the house is empty!