Situation is this: combi boiler, 25 kW maximum output. It's a fairly well insulated 2 bedroom flat, 6 rads total - so 25 kW is way overkill (but of course it's a combi, so it's sized by HW demand).
I've capped the max output to 50% (that's the lowest it will go). Even at this level, the boiler cycles on/off constantly, and overshoots the setpoint by maybe 20 C (eg if setpoint is 50 C, the burner will come on at about 45, burner shuts off a few seconds later at about 50, but the temp keeps rising to about 70 - then temp slowly falls, eventually boiler fires again, cycle repeats).
Is this a problem, and if it is, is there anything I can do about it?
I've capped the max output to 50% (that's the lowest it will go). Even at this level, the boiler cycles on/off constantly, and overshoots the setpoint by maybe 20 C (eg if setpoint is 50 C, the burner will come on at about 45, burner shuts off a few seconds later at about 50, but the temp keeps rising to about 70 - then temp slowly falls, eventually boiler fires again, cycle repeats).
Is this a problem, and if it is, is there anything I can do about it?
