I have added new radiators recently and had a leak at the valves, on the return side, I fixed these and bled the system, and due to the location of the new rads increased the pump speed on my Grundfos UPS15-50 from 2 to 3.
Thought all was well as all evening good heat all round, heating came on following morning and started boiling as the noise was incredible and the radiators upstairs were absolutly boiling. but cold radiators down stairs.
I have since turned pump down to 2 as I thought the additional pump speed would have generated cavitation and air back in the system. Is this correct and how do I balance betwen higher pump pressure to get new rads hot downstairs and boiling water in system? also should i only bleed pump when heating is off?
Thought all was well as all evening good heat all round, heating came on following morning and started boiling as the noise was incredible and the radiators upstairs were absolutly boiling. but cold radiators down stairs.
I have since turned pump down to 2 as I thought the additional pump speed would have generated cavitation and air back in the system. Is this correct and how do I balance betwen higher pump pressure to get new rads hot downstairs and boiling water in system? also should i only bleed pump when heating is off?