I've recently had a new boiler installed - Potterton Suprima HE.
I also have a new programmer - Honeywell ST699 and Room stat - Honeywell DT90E.
The Programmer is a Sundial Y plan with a gravity hot water/pumped central heating system so the heating only works when the water is also on.
The hot water works fine on it's own.
When i have the heating on it fires up ok but when it stops firing, both the water and heating power lights flash on and off simultaneously.
Can anyone offer any help please?