The electric seems to work because when the programmer is used to turn on the water or heating, the 3 port valve seems to work because the pin moves to the relevant port. The boiler doesn't fire up, the pump vibrates.
What is the purpose of the manual open lever and the return spring?
Thanks.
Boiler: Gloworm Spacesaver Mk 2
Pump: Grundfoss
Motorised valve: ? Drayton lifestyle
Everything was working ok, nothing has changed, then there was no hot water or heating. Yesterday the water was heating up but seemed to be taking longer than normal. The electric to the timer controls...