Turning off spare radiators = Cheaper Gas Bills???

katrina1979

Hi

I am new to this but desperatley trying to save money on just about everything so was wondering if i turn off the raditors in spare bedrroms will this mean my gas bills should be less? My radiators are the olsder style so they do not have a thermostat but i reckon i am able to turn off 4 which would leave 5 still on.

Cardew

Welcome to the forum.

Yes the more radiators you turn off the less gas you will use.

The more radiators turned on, the more hot water your gas boiler has to heat. It is really the same question as asking if heating a full saucepan of water uses more gas than a half full saucepan.

I really would pay(assuming you own) to get Thermostatic Radiator Valves(TRV) fitted

katrina1979

Thanks i did think it was an obvious question but had asked a few people at work also and had mixed answer.

Is that something that is possible, can we fit the valves on or do we have to get the newer radiators?

I still have the old back boiler gas heating system which i believe is supposed to be more expensive anyway.

Cardew

Yes fitting TRVs is not difficult or expensive.

http://www.bbc.co.uk/bloom/actions/radiatorvalves.shtml

jamesdrew

I shall keep out of this one but there ARE mixed answers and some will advise you NOT to turn off all your radiators in spare rooms. Central heating is a very different science to boiling a saucepan so I will look forward to reading the technical expert's posts . . .

Cardew

jamesdrew wrote: »

I shall keep out of this one but there ARE mixed answers and some will advise you NOT to turn off all your radiators in spare rooms. Central heating is a very different science to boiling a saucepan so I will look forward to reading the technical expert's posts . . .

What reasons? and why keep out of it when you have raised questions on the validity of the post. It is hardly constructive!!

What technical experts? Give some examples of their advice please.

The analogy of heating a quantity of water in a saucepan or a quantity of water in a central heating system is perfectly valid.

A TRV will turn off every radiator in the house when the room is up to temperature. Why indeed have valves on your radiators if you shouldn't turn them off when not required.

stokefan

yes i agree, surely it just depends where your thermostat is in your house, if its in acold part of the house and you switch the radiators off in that room the boiler will be consistantly boiling??

i think it depends on your set up of your boiler system tbh (im no expert its just my opinion)

LittleMissAspie

Well I once asked my dad about turning radiators down, as opposed to turning the temperature on the boiler itself down. He said that turning radiators down doesn't make any difference because the boiler will heat the same amount of water but it just won't get to the radiators. So I kept the radiator knobs up and the boiler knob down after that. I didn't do any testing by reading the meter though.

Mind you he has a different system to what we had then. We had no water tank. So maybe it depends on that.

kippen_noedel

Here we are talking about thermal conductivity.

Think of your radiators as basic heat exchangers, the more energy they give out the more energy required to maintain the output.

So yes, turning down radiators in seldom used rooms, even taking into consideration the heat loss thru internal connecting walls, will mean you use less energy.

macman

Surely the only argument against turning them off, is that boilers and CH systems are designed to run under a certain load. If you had say a 10 rad system and ran it with only 1 or 2 rads on, it would be way under it's output for efficient running. However that's an extreme case, and I can't see that turning off say 3 or 4 rads out of 8 or 10 could do anything but save energy overall.

Cardew

stokefan wrote: »

yes i agree, surely it just depends where your thermostat is in your house, if its in acold part of the house and you switch the radiators off in that room the boiler will be consistantly boiling??

i think it depends on your set up of your boiler system tbh (im no expert its just my opinion)

I am afraid you do not understand how CH works.

The temperature of the water circulating in a central heating system is determined by the setting on the boiler. That water temperature is usally variable between 60C and 80C.

When the CH is on and the room thermostat calls for heat(e.g. set at 22C and room is at 20C) the pump operates and circulates water to those radiators that are switched on(ie manual valve or TRV open).

The boiler heats this water until it reaches the temperature set on the boiler(the 60C to 80C) and then the boiler switches off(stops firing).

The radiators dissipate the heat from this hot water and when it drops a couple of degrees below the (60C to 80C) the boiler fires up again to re-heat the water to the set temperature.

So the water never rises above the temperature set on the boiler and most certainly never boils!!!

Many CH systems don't even have a room thermostat, although it is mandatory on new installations. They rely on TRVs to control the temp of individual rooms.

The problem with having a room thermostat is that the temperature of the room in which it is situated determines the temperature of the other rooms in the house. e.g. if it is in a living room set at 20C once the temperature of that room reaches 20C there will be no heating in other rooms.

Put it in, say, a cold hall - which you don't want to heat, and you have the opposite problem.

Personally I have mine in a large hall and set it to maximum, but turn off the radiators in the hall. I then control the temperature of the other rooms with TRVs. I appreciate this is not the recommended method as the pump runs all the time. However the boiler obviously switched off when the water in the system reaches the temperature I set on the boiler.

In fact if you read the plumbers forums you will see some plumbers use the same method as myself.