One radiator no longer working after converting from gravity-fed to combi
Anonymous user 23/02/2024 - 3.25 PM
Last year we converted from our ancient gravity fed system to a combi through british gas.
We had one radiator in the extension which, on the old system, would heat up when the hot water came on, but not when the central heating was on.
Now on the new combi system, this radiator does not heat up at all.
Is it just that this radiator used to be connected to the hot water system - and is now not connected to anything? Is there a way of easily checking if it is still connected to the system in any way?
My overall plan is to remove it and replace with an electric radiator, however I would like to work out how it is connected before I go removing anything!
Are you a tradesperson and able to answer this question?
Hi mate it sounds like it could be a few things to me. 1) The radiator that isn't working was previously connected to the return on the old cylinder that you had. Its basically connected to the coil inside the cylinder that used to heat the hot water in the cylinder, thus that radiator becoming hot when the hot water zone valve opens. on that system they would connect the towel rails in the bathrooms to the hot water zone so they don't need the central heating in the summer for instance to have hot towel rails. It could be that it was not reconnected to the ch flow and return. 2) It could just be sludge build up in the radiator itself causing no circulation. You can close both valves fully, remove the radiator and fire the system up. Once it Heats using a bucket over one of the valves , open it and see if its pressurised. if your able to let it flow through for a while you may flush it through.
I hope this helps you mate
All The Best
Gavin Arnold CEO
The answer is in the question ....As you rghtly said ....it was connected to the hot water system and would only worked work when you have stored hotwater.
this is very commom on older type of conventrinal tye of systen and usally the bathroom radiator is operated via the hot water supply. Now that you have instant hot water the radiator will not work.
To solve the problem you need to drain down the heating system and re-install the radiator and join it to the heating system pipeworks flow and return and remove the hotwater link from the hot water pipe.
The same would apply if you install a towel rail type of radiator that relies on the boiler to heat it up.
An electric radiator would be simplest to install providing it is small and do not require a diret feed fron the consumer unit,.you need to check with the manufacturer specification for thair installation manual.
If British Gas fitted your combi, they should have spotted that the radiator you mention was connected to part of the system which was not being replaced and re-plumbed it accordingly.
Doesn’t take a rocket scientist to work that out.
If I were you and for the price you will have paid I would get onto them ASAP and ask them to come and make the radiator work. (Unless you specifically excluded that rad when you had the new boiler fitted, in which case it shouldn’t cost more than a couple of hours work for a competent plumber).
Guy
