The Efficient Home Forum

https://www.libble.eu/honeywell-hr91/online-manual-863935/?page=0002 To find out which valves are open/closed you need to get to the hidden settings Press the settings icon for more than three seconds press the green tick press system summary This will show % of the valves that are open/closed There ...

Check your motorised valves are working. The motors due go faulty and will not send the trigger to the boiler. Depends on your heating system weather you have one 3 port valve (y Plan) or two one way valves (s plan). If you hot water is working as it should the I would guess you have two one way ...

I've had this before.
Try setting the desired temp manually by turning the dial on the affected valve. This cleared it for me

Hi, You could have stuck pins on your radiator valves. The boiler will not fire until it see's approx 40% open. If your valves are only opening 20% this will not cause the boiler to fire. To see what is happening with your valves 1. Press settings for more than 3 seconds 2. Press the green tick 3 ...