I had a new rad installed last year and the system ran ok for a few months. Now seem to have air trapped in the system as it bangs loudly. Turning up the pump speed reduces but does not get rid of banging, I have drained and refilled the system two different ways (bottom up and top down) but this has not fixed it. There seems to be lots of air in the boiler area, which keeps knocking the boiler off. I have a Potterton Fuelsaver F boiler, does anyone know if this has an air bleed screw?
I have had a plumber out to try and fix this problem without any joy.
Additionally, I think the 3 port mid position valve may have stuck in the mid position as the manual lever does not move when only heating or only hot water is selected. I would be grateful for any suggestions or help.
