sealed central heating system

[jobloggs49]

Hi

Just moved house. Oil fired CH is a sealed system with small pressure tank in roofspace. I need to change a valve on one of the radiators (all on ground floor). There is a drain cock on the front of the boiler at the bottom.

However I am unsure of how to recharge system after valve is replaced. Is it more complicated than opening the feed valve to the pressure tank?

I intend closing all valves to all other radiators to avoid them emptying but am unsure how any air in the pipework and the affected radiator would escape as the pressure cylinder is at the highest point.

Any advice would be gratefully received.

 

[Diyisfun]

Bump
I think. its do as you have said & then bleed ALL the rads.

 

[hanns21]

Open the drain valve below boiler. About a bucket of water should come out then the water will stop. As no air can enter the water wont drain.change your valve then top up water pressure untill 1bar using filling loop