Central Heating

[sinistra]

I have been told I should have my heating on 24/7 at 15 degrees to protect the property and prevent pipes freezing. I can't see it being cheaper than putting it on as and when I need it i.e. an hour in the morning and a couple of hours in the evening at 20 degrees. Which would be the most efficient and cost effective? My pipes are lagged and the loft is fully insulated.

[Gizmonster]

There have been lots of discussions on this and to be quite honest, I'm with you.
As long as your house/pipes are insulated efficiently, I'd agree that an hour or 2 in the morning and a few hours in the evening, should be sufficient at keeping the house warm and should be a lot cheaper than keeping the heating on 24/7.

[KARL]

Consider this: To compare consumption, you drive your car twice a set distance over the same course lasting, say, some hours.

First you set off at full throttle until you reach the car's maximum speed, then you switch off the engine and coast until the car comes to a halt. At that point you start up again, reach maximum speed and coast to a halt. You repeat this until you cover the set distance.

The second time you start up and drive at a constant speed, say 50 mph, until you complete the set distance.

Which driving method do you think will produce the better consumption ?

Now consider maintaining a constant (low at 15 degrees) temperature throughout the house against firing up to 20 degrees (if you ever manage to reach that in an hour) twice a day from whatever it has fallen to. I can tell you one thing, you are very unlikely to risk condensation being found in the former course whereas you are rather likely to experience it in the latter. It gets a lot worse if you are only heating part(s) of the house. I know people who have tried both (intermittent heating versus continuous) and they now heat constantly (to nearer 20 degrees) and say it is surprisingly cost effective - and they acknowledge it is far more comfortable because our bodies feel chilly as temperatures fall. You are proposing to create falling temperatures for 21 hours out of 24.

[Gizmonster]

It all depends on what exactly your needs are; when you're home and how warm you want it.
If you're out of the house during the day (like me and my missus are), then there's absolutely no need to have it on 9-5 when the house is empty. Assuming you've got adequate insulation, etc (which it looks like you have), your pipes will not freeze during the short period of time that you're out and the house temp prob won't drop that much anyway.
Sometimes I get home from work early (before the central heating has come on) and the thermometer usually reads 14 deg C or above (even on very cold days), even though the central heating has been off for approx 7 - 8 hours.
If, however, you're at home most of the day and want to be nice and toasty .......

[bookbinder]

My wife and I are both retired, so we're at home for most of the time. I experimented a few years ago with putting the heating on timed (on for a couple of hours in the morning, off during the day, on from teatime to bedtime), from Oct. to end of March, then leaving it on 24/7 for the same length of time. This was done over two winters. I found that it was cheaper to leave the heating on 24/7, at about 18 degs during the day then 16 degs at night. I reckon that more fuel is used with the on/off twice a day system, because when the boiler fires, it has to heat up a stone-cold house. With the heating on 24/7, but turned down fairly low, the boiler just needs to keep the heat ticking over, as you might say, and doesn't have to work hard at heating a cold house.

[ummmm]

Doesn't it depend what type of boiler you have?

[EcclesCake]

How modern is your glazing?

An incredible amount of heat can be lost through old windows, double glazing included.

[atalanta]

Some scientific tests were done some years ago. They were done solely for cost reasons - to see which method was cheaper, not to see if pipes froze. The scientists found that it only paid to keep the heating on permanently in old stone houses which could not be insulated like modern houses.

[Wak]

I would think that the best way to find the cheapest method is try both methods when the weather is settled and fairly constant for a couple of days and to take the gas meter readings at the start and end of each method.