Adding a room thermostat?

[Lorenzo]

We have a gas central heating system. Each radiator has an individual therostatic valve to turn flow off when it reached the right temperatute. However when all of the radiators have turned themselves off, the water just runs through the two bathroom radiators until the end of the timed heating period.

It seems a waste to have the bathrooms being heated unnecessarily so we try to turn the system off for a while as soon as the living areas reach their temperature. I wonder if a room thermostat is suitable for this type of system to put the power off and on again as the temperature in the living areas fluctuates?

Many thanks for any advice.

[EricP]

Your system is operating exactly within design specs, as was my identical one, less than a year old.

I felt as you do and bought an RF thermostat/programmer. I estimate savings have been about 40% of the bill by having the extra control, as mine is on virtually 18 hours a day.

It seems that the RF control was overkill as it has ended up in the hall in the same place that I would have put a £10 wired one.

[Andrew Gabriel]

Actually, it's been illegal to install a system which works this way since April 2002, and also any boiler change since that date in such a system requires that the system be brought up to current standards. Boilers installed since April 2002 must include a boiler interlock which shuts off the burners when there is no call for heat (i.e. all rooms up to temperature). This is most commonly done by using a roomstat in one of the rooms (ideally the longest to heat up), and don't use TRV's in that room (or set them to max or take the heads off if they're already there).

The associated energy saving is why such schemes were outlawed in the 2002 Building Regulations.

[Keith Dunbar]

Sorry to be ignorant but what is RF?

Keith

[Derryck Croker]

Radio Frequency.

In this case, the thermostat uses a radio frequency to send control signals, rather than using a wired connection. Hence, you can move the thermostat around the house without worrying about dragging a long length of cable around :-)

[Lorenzo]

How much did that cost please? Is it something I would need an electrician to install (I wouldn't want to do anything risky myself!)

Many thanks.