Andy,
I am in over my head. I would not know the difference. I am assuming that I have zone valves.
The plumber came out, as we have small children, and said the fan needed to be replaced. The ignition start process was doing all the right steps up and until the fan was required. At...
First time on list and I have checked for previous threads on this so apologies if this is already been covered somewhere.
I have an extension with a new boiler a Wochester Bosch Greenstar24 Ri. (2007).
The thermostatic system is a Drayton Tempus 3 that came with the original house...