I have a Glow Worm Ultimate 40 conventional boiler and a standard vented heating system.
When the house is cold and the CH is switched on, the boiler will run as normal for about 20 mins, then cycle on for about 1 min then off for about 3 mins until eventually the room stat cuts the boiler off when the house is up to temp - but this take about 5 hours or so.
The boiler stat is set to about three quarters, the room stat set to 22 C, and the TRVs opened up all the way.
The circ pump is only on setting one (the slowest) so my guess is the pump isn't shifting the water away from the boiler fast enough, causing it to cut out as it should. (if i have the pump set any faster, i get overpump (and a noisy CH system) and overflow from the F+E tank). Is this actually whats happening? If so, is turning down the output of the boiler the answer?
Cheers
When the house is cold and the CH is switched on, the boiler will run as normal for about 20 mins, then cycle on for about 1 min then off for about 3 mins until eventually the room stat cuts the boiler off when the house is up to temp - but this take about 5 hours or so.
The boiler stat is set to about three quarters, the room stat set to 22 C, and the TRVs opened up all the way.
The circ pump is only on setting one (the slowest) so my guess is the pump isn't shifting the water away from the boiler fast enough, causing it to cut out as it should. (if i have the pump set any faster, i get overpump (and a noisy CH system) and overflow from the F+E tank). Is this actually whats happening? If so, is turning down the output of the boiler the answer?
Cheers