Central Heating - Cheaper on all the time?

bikeman

I am one of those convinced that leaving gas central heating on all the time saves money BUT what we actually do is switch between 2 temperatures (16C at night/unoccupied time and 19C during the occupied day/eve) over a 24 hour period.

The heating will generally only come on during the coldest nights. After these coldest nights the CH boiler has less work to do to bring the house back up to 19C and this is how we get savings.

All I can say is since we started doing this our consumption has dropped appreciably.

ps I have a 4 bed detached house and pay £30 a month for gas (for heating plus a gas hob). I should also add that our HW is set for 55C and our boiler at 66C - I think not setting your boiler unnecessarily high must also help.

grahamc2003

bikeman wrote: »

I am one of those convinced that leaving gas central heating on all the time saves money BUT what we actually do is switch between 2 temperatures (16C at night/unoccupied time and 19C during the occupied day/eve) over a 24 hour period.

The heating will generally only come on during the coldest nights. After these coldest nights the CH boiler has less work to do to bring the house back up to 19C and this is how we get savings.

All I can say is since we started doing this our consumption has dropped appreciably.

ps I have a 4 bed detached house and pay £30 a month for gas (for heating plus a gas hob). I should also add that our HW is set for 55C and our boiler at 66C - I think not setting your boiler unnecessarily high must also help.

What i don't understand from your explanation is why you think you save money by not letting the temperture drop below 16 degrees, yet you happily let it cool and heat it up from 16 to 19. Why isn't it cheaper, according to your assertion, to keep it at 19 all the time?
Don't you see the paradox in what you say?

The situation is remarkably simple. You boiler has to replace the heat lost from your house. The warmer your house is, the more heat it loses. (The radiant heat loss for example is proportional to the temp difference to the power 4, so a 2 degree difference betwene inside and out will cause 16 times the heat loss by radiation than a 1 degree differnce). Given we can't control the outside temp, the only infliuence we have is the inside temp. So the lower the inside temp, the less the heat loss, and the less the boiler has to work. So if you maintain 16 degrees instead of letting the temp fall to 15 degrees (or 5 or zero degrees) then you'll lose more heat, which your boiler will eventually have to replace. You may think you are losing less gas by your strategy, but I'm afraid it is impossible that you are.

Others have been talking about the comfort factor, and obvioulsy it may be more comfortable to keep the house warmer, but that wasn't the original question.

Btw, I'm not trying to influence anyone in the way they use their heating - just informing that the warmner you have your house, the more you'll pay (something I'm sure you accept). But that applies not only having it at 24 instaed of 23 when you are in, but also having it at 16 instead of 15 or 5 or zero when you are out.

Vicky123

Maybe I'm a particularly cold person but I find it takes all day of constant firing up to get our combi to a temperature we are all comfortable with which is 21, this is a big detatched house though.
I thought the idea of all the thermostats is that only when the temperature drops below what is set will the boiler fire up.
Clearly I know nothing of physics but I can hear it firing a lot all day and also feel very cold most of the day. Doesn't all the firing up cost more money?
Vicky

closed

£30/month for heating a 4 bed house (more or less 24/7) in this weather? Does that £30 actually cover your usage? Turning the stat down has the same effect as using a timer if you turn it low enough.

Firing up does cost money, what type of thermostats do you have, what are they set to, and what is the room temp

Vicky123

Mine doesn't cost £30 a month we are on dd for £70 per month!
Radiators are all at max which is 5.
Boiler is a big baxi combi, but have now gone and looked at the boiler and the setting on that was in the middle, have now turned it up, feel a complete numpty now, assuming that is why we were not heating up, but what's the point of having a temperature on the wall and then another one on the boiler, which one is it working from?

closed

£30 was directed at bikeman

Radiators shouldn't be set at max in every room, that means they will never turn off when the room gets to temp.

The room thermostat usually in the hall, should be a couple of degrees higher (initially) than your desired house temp, to ensure it doesn't override heatings in colder rooms

welda

Vicky123 wrote: »

what's the point of having a temperature on the wall and then another one on the boiler, which one is it working from?

My current NGCH system I had designed by a colleague who used to work with a well known merchants. When it came to where to locate thermostat, this was a dilemma.

As new rads would have TRV's fitted, it was decided our two en-suite rads with towel rail incorprorated would be the bypass rads without TRV's. I use stat on the boiler, at the moment set at MAX, as we move into spring and summer, I then adjust down the scale to normally half way, odd time I may have to knock it up a tad if spring is cold?

As boiler is located in outside boiler house, I have a frost stat installed, I have this set to kick in at 0c degree, when it does kick in, it does put heat into rads and of course house, frost stat main point is to protect system from freezing, will burn a few therms, then switch off.

Frost stat is peace of mind, especially if a boiler is installed out with a house. In answer to your question which one is working, I guess both are?

:beer:

Cardew

Vicky123 wrote: »

but what's the point of having a temperature on the wall and then another one on the boiler, which one is it working from?

The thermostat on the wall controls the air temperature in that room. When the room reaches the set temperature, the CH switches off until the room cools down a couple of degrees and then the boiler fires up.

The thermostat on the boiler controls the temperature of the water in the CH system(pipes and radiators). The higher the temperature of the water in the radiators, the quicker the rooms heat up. The water can be as hot as 80C+ which can make the radiators liable to burn infants.

2010

The temp on my hot tank in the airing cupboard is set at 60, should it be moved higher in this cold snap and to what?

Cardew

2010 wrote: »

The temp on my hot tank in the airing cupboard is set at 60, should it be moved higher in this cold snap and to what?

No. That is the temperature of the Hot water for taps - not the hot water in the radiators for central heating.

There is normally a control on the boiler itself(often marked 1 to 6) that controls the temperature of water for the radiators. Having it turned up will heat the house up quicker.