Can you retrospectively fit a thermostat to central heating?

missimaxo

We purchased our house 5 years ago... the central heating is a gas fired combi boiler with a timer dial where you set the times it comes on, a knob to select hot water or both hot water and radiators and then 2 dials to choose the hot water temperature and radiator temperature. These two latter dials are not set with degrees, but just a sliding scale to pick from.

Around the house we then have the radiators, each fitted with those large white knobs with numbers 1-5 on them. To me these seem useless, they all have to be set to 5 or the radiators just don't come on. The only way we can control the heating is to use the boiler, randomly select a temperature and then choose rads on or off.

I would love a thermostat like my parents have... sttached the the hall wall, that means if the temp is below eg. 18degrees the rads come on, if above then they don't. We waste energy as if its is warm when I am out at work, the radiators come on if set to come on and then the house gets too hot, ditto the opposite if it is cold. This constantly having to be on top of turning the heating nand off is doing my head in!

Can a room thermostat be retrospectively fitted to the system? If so how much would I be looking at? We are having the hall replastered this year so it would make sense to do it now for channelling cables.

Thanks

closed

are you saying (when the house is cold) no hot water goes into the radiator at all if the trv is set at 1234?

yes you can retrofit a thermostat, but trv's (when working) give far better control

if the house is too hot, the trv's are set too high.

missimaxo

Apologies - I don't really knowthe terminology. I presumeby TRV's you mean the white things attached to the radiators.

In answer to your question.... yes, the radiators do not get hot unless they are set to full. I never really understood how they worked and because they only worked on 5 then I presumed they were just fancy on/off switches rather than using the smaller knobs that you used to get on radiators, that open and close the valves.

closed

thermostatic radiator valves.

they work by turning off when the room gets to temperature, the radiator will then go cold, which stops the room overheating, and saves energy bills.

if the house is cold, then a setting of 3 or 4 should allow hot water through, until the room gets warm, then it goes off.

missimaxo

In that case I will have to look into why these are not working. I know for definate last spring when we had the mega hot weather, I left the boiler turned on by accident and still all the radiators came on.

macman

The control on the boiler does not control the rad temperature (at least, not directly). It controls the temp of the water entering the CH flow circuit.
For proper local control you need (working) TRV's and a room 'stat. At present you are just throwing money away.
A wireless room 'stat or digital programmer is an easy, cheap, and very worthwhile retrofit. No wall channeling required. 'Stat from £15, programmer from £60.

closed

missimaxo wrote: »

In that case I will have to look into why these are not working. I know for definate last spring when we had the mega hot weather, I left the boiler turned on by accident and still all the radiators came on.

because they are set at 5, which is too high

jbainbridge

A room thermostat is what you want. Then once the room reaches the correct temperature the heating turns off - saving you money and making you more comfortable. TRVs are used in addition to the stat.

It will need to be wired into your boiler. A wireless one will save you having to run a cable through the house. You can also get 'programmable' ones too which will include the clock function too.

Mr_Ted

Current regulations insist on a room thermostat being fitted at a time of retrofit, along with many other items!

Your installation was probably outside ot the regulation coming into force, however even prior to this a room stat was always advisable even with TRV's, but many didnt use one!

Installation of a room stat as you state in the hall, which is the advisable place, is not particularly difficult or expensive!
If the boiler is fairly new(type manufacture and model needed) it can often even be just a twin voltage free connection?
It should be remembered though that the radiator in the area the room stat is fitted SHOULD NOT have a TRV!
TRV's are very prone to sticking unless they are manually manipukated regularly, but can often be freed up fairly easily?

diywhynot

Guidance on current heating and DHW controls requirements is available here.