To leave on or not?? Gas CH question

[spantik]

Bet you've answered this question more than once!

I had a Vaillant combi boiler & programmable room thermostat fitted at the start of the year. The heating is on after the summer and I am left wondering the age old question - is it more economical (and more efficient?) to set the thermostat at a comfortable room temperature throughout the day (and night?) even if I'm in and out of the house OR should I set several programmes of different temperatues eg 1) night 2) day 3) evening?

If, following on from a cooler night time setting, the boiler has to work hard to attain the day time temp I've set rather than just carry on maintaining ONE day/night temp. is this less economical and efficient?

If you suggest it's more economical to maintain the same temp throughout night and day I could keep the bedrooms cooler using the rad. thermostats.

Economics is the main reason for asking but also maintaining the efficiency of the boiler.

Your views please oh! wise ones. Thanks for a really useful forum.

[htg engineer]

It's all down to personal choice/preference, I've never heard or seen of a definitive answer. Air Source and Ground Source heating systems don't get as hot as a typical heating system, therefore the radiators are oversized and are best used 24/7. I used my gas heating system like this last year, as my wife and 2 children were at home most days. This year my wife is back at work and the children are at school/nursery so we're using the heating on timed for a couple of hours before we leave the house and a few hours in the evening. I didn't take any notice of the cost last year - maybe I should have it would have been interesting to see the price difference.

htg