I changed it a couple of years ago and it worked so I thought it might be the same problem again. But it didn't work this time.
Just trying to look for a new controller/program box nowthe one I have is old so I'm guessing that some wiring will be needed
Thanks for the help
Yes it's a system boiler, I have changed the Honeywell three way valve, when you say programmer do you mean the controller which you can switch on water or central heating or set timers?
I have a old wallstar 15/20 boiler, I have green power light but nothing else, no red reset or limit light on, no hot water or heating..tank full of oil....any advise appreciated