I have been experimenting with my system some more.
I have a potterton suprima 40L boiler in a 3-bed flat with 7 radiators, one of which is currently out-of-circuit. The CH and HW are on separate zone-valves. I emptied the old water out of it and filled it with new (plus fernox inhibitor & wickes leakseal) last night. filled the rads, and ran it up for a couple hours:
The suprima has a heat control knob which I set to minimum (but not clicked off), and I had the pump at speed-3 (its maximum). rads got plenty hot, and the system seemed to reach steady-state without problems. The ventpipe was pouring "spent" (hot but not scalding) water back into the F&E tank quite fast though (kettling?); the tank was steaming, probably water at about 60-70 C. obviously undesirable.
I turned the pump to min.speed and this stopped the kettling, but after a while the boiler started grinding, I think it was boiling coolant,
I feel this is because the coolant is becoming stationary - spending too much time in the boiler before passing out to the rads???
I also get the feeling the system was installed a bit bodgily. grey plastic Hep' pipes are in use around the boiler (copper everywhere else), and my gut feeling is that the boiler power output is too high for the system.
I was also surprised that even at boiler heat control at min, the rads are still VERY hot. could it be the heat control is bust? should there be thermostatic action in the boiler?
"curioser and curioser"... I don't want the system kettling with the pump at max, but I cant seem to avoid this without making the bastard boil!!
Help & comments are very much appreciated - and Thank You all very much for the help so far. I've got to say this is the best use of the www I have seen yet!
I have a potterton suprima 40L boiler in a 3-bed flat with 7 radiators, one of which is currently out-of-circuit. The CH and HW are on separate zone-valves. I emptied the old water out of it and filled it with new (plus fernox inhibitor & wickes leakseal) last night. filled the rads, and ran it up for a couple hours:
The suprima has a heat control knob which I set to minimum (but not clicked off), and I had the pump at speed-3 (its maximum). rads got plenty hot, and the system seemed to reach steady-state without problems. The ventpipe was pouring "spent" (hot but not scalding) water back into the F&E tank quite fast though (kettling?); the tank was steaming, probably water at about 60-70 C. obviously undesirable.
I turned the pump to min.speed and this stopped the kettling, but after a while the boiler started grinding, I think it was boiling coolant,
I feel this is because the coolant is becoming stationary - spending too much time in the boiler before passing out to the rads???
I also get the feeling the system was installed a bit bodgily. grey plastic Hep' pipes are in use around the boiler (copper everywhere else), and my gut feeling is that the boiler power output is too high for the system.
I was also surprised that even at boiler heat control at min, the rads are still VERY hot. could it be the heat control is bust? should there be thermostatic action in the boiler?
"curioser and curioser"... I don't want the system kettling with the pump at max, but I cant seem to avoid this without making the bastard boil!!
Help & comments are very much appreciated - and Thank You all very much for the help so far. I've got to say this is the best use of the www I have seen yet!
