Cheapest way to use gas central heating

Likestowrite

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I've recently had full gas central heating installed (combi boiler) but won't be using the radiators until the weather gets cold. So I'm wondering...

My daughter is at home with children and doesn't go out to work. She always switches off the heating at her own house whenever the house starts feel a bit too warm and turns it back on later when she starts to feel chilly. ( She has it off at night as her bedrooms hold the daytime heat. And always switches it off when she goes out and the house will be empty.

But other people say you're not saving any money by doing this as letting the house get cold then warming it up from scratch is a more expensive way of using central heating.

I have a wall thermostat set to 18 degrees. It's timed to switch the central heating off at 11pm and come on again at 7am. (I'm planning to use woollen blankets and hot water bottle at night for my bedroom and as long as the room temperature doesn't fall uncomfortably low I'm not planning to keep the heating on at night) I'm retired so don't go out of the house except to visit family and go to the shops. I plan to have the radiators turned off (or on a very low setting) in the 3 unused bedrooms.

If I leave the heating on all day, set the radiators I'm using to the highest setting (5) and rely completely on the 18 degree thermostat timer setting (heating set to be on on all day but controlled by the thermostat-- and off at night) is that the most economical way to heat my house? Should I aslo switch off the heating if I happen to go out for a few hours?

HappyMJ

The cheapest way to use central heating is to have it turned off.

Any period of time when it is off will save you money. So I'd turn it off if you go out.

What people tend to do when they make these comparisons is all day on 18 compared to two hours in the morning and four hours in the evening set at 25 degrees? Then and only then in that scenario could it be cheaper all day as the boiler is running on full as opposed to 15 minutes every hour to maintain the temperature at a low temperature.

macman

There are literally hundreds of threads on this subject...usually starting around October.
Analogy-do you keep your kettle just below boiling 24/7 in case you fancy a cuppa, and it would be cheaper not to let it go cold?
The longer your heating is on, the more it costs you. It might be more convenient, but it's certainly not cheaper.
Over what period do you think it would be cheaper to leave it on? A few hours, a day, a week?

Likestowrite

HappyMJ wrote: »

The cheapest way to use central heating is to have it turned off.

Any period of time when it is off will save you money. So I'd turn it off if you go out.

What people tend to do when they make these comparisons is all day on 18 compared to two hours in the morning and four hours in the evening set at 25 degrees? Then and only then in that scenario could it be cheaper all day as the boiler is running on full as opposed to 15 minutes every hour to maintain the temperature at a low temperature.

Thank you. Having the thermostat turn the heat on and off during the timed period might not be as economical as I thought. I should maybe switch it off manually whenever the house starts to feel too warm and put it back on when I feel too cold.? I'll switch it off when I go out and definitely keep it off at night.

I'm not sure how to use the individual radiator valves. I'll turn them off in the bedrooms I'm not using. But what setting should I have them on in the rest of the house? If I have them on the highest setting does this mean the room will get to the pre-set temperature quicker than on a lower setting? And this will be the best setting to have them on?

HappyMJ

Likestowrite wrote: »

Thank you. Having the thermostat turn the heat on and off during the timed period might not be as efficient as I thought. I'll switch it off manually whenever the house starts to feel too warm and put it back on when I feel too cold. I'll switch it off when I go out and definitely keep it off at night.
I'm not sure how to use the individual radiator valves. I'll turn them off in the bedrooms I'm not using. But what setting should I have them on in the rest of the house? If I have them on the highest setting does this mean the room will get to the pre-set temperature quicker than on a lower setting?
And this will be the best setting to have them on?

No...and my OH don't understand this either. It will get to the preset temperature at the same speed no matter what you set the thermostat to. If you set it to max though it will cost more as the boiler will keep on running trying to get the room even hotter and eventually you will have the room too hot and therefore wasted money heating it higher than you need.

Set the TRV's to the lowest setting...if it's too cold then turn them up a little at a time until the room is at a level which is just warm enough.

Personally I've given up with the timer and just use the thermostat to control the heating. It's lowest setting is 7 degrees which I doubt it will fall to on most winter nights bt if it does then I don't mind it coming on to add a little more heat. When I need heat in the evening I just turn it up and the heating comes on.

Likestowrite

HappyMJ wrote: »

No...and my OH don't understand this either. It will get to the preset temperature at the same speed no matter what you set the thermostat to. If you set it to max though it will cost more as the boiler will keep on running trying to get the room even hotter and eventually you will have the room too hot and therefore wasted money heating it higher than you need.

Set the TRV's to the lowest setting...if it's too cold then turn them up a little at a time until the room is at a level which is just warm enough.

Personally I've given up with the timer and just use the thermostat to control the heating. It's lowest setting is 7 degrees which I doubt it will fall to on most winter nights bt if it does then I don't mind it coming on to add a little more heat. When I need heat in the evening I just turn it up and the heating comes on.

Thank you. I'm still a bit confused though. (Sorry if I'm being a bit thick but this is all new to me) My programmable wall thermostat (in the hall) is set so the heating comes on when the temperature falls below 18 degrees.

If I have the individual TRVs on low in the rooms I'm using, will the radiators heat the rooms to a lower temperature than 18 degrees ---and I'll need to turn the TRVs up a bit if the room seems too cold?

If I set the TVRs on the highest setting the boiler will constantly try to heat the room even higher than the pre-set 18 degrees and keep on running?

HappyMJ

They'll heat to whatever temperature they get to. Only once the hall gets to 18 will they stop heating. Many people have a cold hall and the living room might be 3 or 4 degrees warmer than what it says it is on the thermostat in the hall. So it might be 21 in your lounge and you feel comfortable even though the thermostat says it's 18. 21 is normally when most people feel very comfortable.

Likestowrite

HappyMJ wrote: »

They'll heat to whatever temperature they get to. Only once the hall gets to 18 will they stop heating. Many people have a cold hall and the living room might be 3 or 4 degrees warmer than what it says it is on the thermostat in the hall. So it might be 21 in your lounge and you feel comfortable even though the thermostat says it's 18. 21 is normally when most people feel very comfortable.

Thank you for explaining all that to me. Your replies were very helpful.:)

I think I get it now. I start with the TVRs in each of my two downstairs living rooms low and turn them up until the rooms feel comfortable. (Because the hall will probably be colder than the living room and because of that I could end up with my rooms a lot hotter than the 18 degrees I wanted. And this will cost me and be a waste of money)

If I find (once I switch on the heating) that I'm having to turn the room TVRs to the highest setting to feel warm, will that mean I need my hall thermostat set a bit higher so I can turn the room TVRs down to a lower setting?

Maybe I should move my wall thermostat into the living room so I get a more accurate temperature? (The engineer got the best signal in the hall but there might be somewhere in the living room that would be okay)

macman

The TRV is just a zonal thermostat. It alters the temp at which the valve opens and closes. It doesn't affect the speed of warm up at all.

Likestowrite

macman wrote: »

The TRV is just a zonal thermostat. It alters the temp at which the valve opens and closes. It doesn't affect the speed of warm up at all.

Thank you. So the TVR won't heat a room quicker it will just heat it to a higher temperature.

ic

If you decide to move your thermostat to the living room, bare in mind:

- you must turn the TRVs on the radiators in the living room to max, otherwise they may cut off before the thermostat has reached its temperature - the result being the thermostat is calling for more heat, but never gets it as the radiators are off = boiler running endlessly.

- your living room might be comfortable, but other rooms may never reach full temp before the thermostat turns off the boiler. In a good system, the radiators should be sized and balanced to the room - so all rooms should heat up at the same rate.