TRV's for single pipe system?

curiousb

We have a single pipe central heating system in our house, e.g. there is not a return pipe from each radiator to the boiler.

We are replacing the downstairs radiators but have been told we can't get thermostatic valves for the radiators to this single pipe system.

Does anyone know this to be true? Or is there TRV's available for such a system?

We don't have the money to redo the heating system, so we need to make it as efficient as possible.

dpofloinn

Yes and No. You can't use regular TRVs on a one pipe system. Although the single pipe system's have pumps the radiators are heated up by gravity, the valves for 1 pipe systems have a larger body so they have far less resistance to flow.If you throttled any part of the single pipe it would affect all the radiators. There are special TRVs for single pipe systems they have a much larger valve body such as the danfoss randall rag single pipe trv. Ive Never used one so I can not say if they are any good or not

curiousb

OK, thanks for the info. I'll make a few calls to plumbing shops and see what they have.