Heating system not filling

[steviemod]

Hi, I have a microbore system with Potterton Gas Heating - It is conventional setup with exansion tanks and immersion heater tank. Recently the system has starting banging loudly so I checked for air locks. What I mistook for the 'hiss' of the radiator being bled turned out to be the 'hiss' of the system sucking in air so it's not filling although the loft tank works OK. The banging turned out to be boiling water in the expansion pipe discharging into the tank. I have neither central heating or hot water so if you can shed any light on this I would be very grateful. Thanks Steve

 

[Tibbot]

Probably blocked cold feed pipe.

 

[Nige F]

Indeed - try it with a magnet round the pipe , it`ll find the metallic c*** inside blocking it

 

[mysteryman]

Try venting it with everything turned off, so that the pump is not running. That can cause a vacuum.

 

[Whitespirit66]