Installing TRVs - Radiators

krishing

Hi folks
This is a bit longwinded, but I'd be grateful for advice.

I have bought some trvs to install on my radiators. Some of the radiators are quite old. The existing values have three quarter inch nuts, but the trvs have half inch nuts. They also come with an adaptor to screw into the radiator which have an olive and the locking nut assembled as a single piece (you can't really separate the items). Of course I could start the job and find out but maybe someone has some tips. Would I be able to use the existing lock nut to screw onto the valve, or, will I have to remove the old valve and the adaptor to make way for the new one? If that is the case, will the new adaptor fit the radiators bearing in mind some are really old (ie they have no convector fins).

In any event if it is not too difficult, I'd like to replace some of the radiators, but some seem to be of unusual size ie 1140 mm by 730mm. So where could I get advice on adjusting the existing pipework to fit, bearing in mind I may even replace a single radiator with a double. I've tried the local plumber's merchant but it was of limited help.

Hope this makes sense and that someone can advise.

Regards

Krishing

gas4you

You need to remove the tails for the old valves (3/4"), then fit the 1/2" tails from the new valves, for them to fit onto.

Removing the old tails can be problematic occasionally, especially if you are using a basic rad spanner.

Go for the nearest size under the rad size you already have, then you buy extensions to make up the difference.

krishing

Many thanks. If replacing a single rad with a double, would I need to move the pipe away from the wall to allow extra space? Is it advisable to do this by "bending" the pipe away from the wall. If possible, I'd like to avoid lifting floorboards and cutting pipes. I know what you mean about removing adaptors with a rad key. Previously I suceeded by removing the rad and using an extension bar.
Regards
Krishing