DIY Doctor UK DIY Forums

Please help me. I need to make space adjacent to a radiator which means moving a TRV from a horizontal to a vertical position. Do I need to drain the whole system bearing in mind I am in a groundfloor flat and it is a combi run system. I am so ignorant about these things. Could it be possible that I do not even have a header tank?
Your help would be much apprecited

Some combi boilers are tank fed, but if you're in a downstairs flat I wouldn't think yours was.

Do you have to top up pressure on boiler, using a combi fill ? If yes then there's no header tank.

Yes you will need to drain system to change TRV.