Hi ,Ihave a Potterton Suprima 30L-50L which is in the loft so it is a pressured system. Every year in the summer, when the heating off at about this time, It starts to make a churning sound when its pumping. I've tried bleeding the radiators, but this has no effect.Can any body help me please!!!!

steve c, July 2009

thank you very much, that seems to have cured the problem kind regards, steve.

steve c, July 2009

look for a bleed point around the hot water cylinder and at the highest point on the system and try that. also you can try to bleed the pump using the screw on the front of it.

Ian, July 2009