I have fitted replaced a Honeywell ST699 with a Drayton LP 241.


I have connected up the way the compatibility table says but cannot get the HW 'only' to come on. This is for a heating system with a back boiler behind the fire and the pump in stairs cupboard with water tank upstairs.
I have put the links in L-5 and 5-8 but still no joy. Any ideas would be great thank you.