TRVs - do they save money or just improve comfort levels

ilikecookies

As per the title I'm looking for views on the merits of fitting TRVs.

The context is that we are on oil (boo!) and next year we plan to add a couple more rads and also upsize a couple of existing rads to try to make the house warmer as the current rad provision is undersized for the house. As such most plumbers are trying to sell us TRVs into the work.

Now I can see that TRVs can help improve comfort levels by enabling you to reduce the output of a radiator but I'm unclear if this achieves a cost saving, ie. if we chose to run all the rads at half-power on TRVs would there be any cost saving versus running all rooms at full power today?

The reason I ask is that as I understand it TRVs do not act as boiler interlock and so will not stop the boiler firing. However I imagine if the rads are requesting less heat then the boiler won't need to be on as long (assuming of course that the room with the thermostat in is hitting the required temp).

Your views would be appreciated!

Cardew

TRVs are now mandatory for new CH installations - allthough you could have them at maximum or even remove them completely.

All a TRV does is 'automatically' turn the radiator off and then back on so that the room will keep at the temperature you require - say 20C.

Without a TRV there would be no control of thetemperature in individual rooms; everything would be determined by the setting of the wall(room) thermostat - which can only be in one room. All rads would produce maximum heat until the room stat set temperature was reached and the boiler shut off.

So if you have your room thermostat in the lounge set to, say, 21C, you can choose to have one bedroom at 12C another at 16C etc