Potterton netaheat 10-16 Boiler
I drained down the system to install a new radiator upstairs, refilled system and bled the rads starting upstairs. Now there is a gurgling noise coming from the flow and return pipes and boiler as if it has still got air in the system, any ideas what the problem could be??

Guy, July 2009

air still in system. isolate one rad valve and bleed then isolate other valve (opening 1st valve) and bleed.

guy, July 2009