I'm replacing Programmer Horstman H27XL with a Honeywell ST9400C but having problems with the wiring as the Horstman had 9 connectors and the Honeywell has only 7.
I've attached a photo of the Horstman wiring and a photo of how I've wired in the Honeywell.
I don't think it's heating the water...
Had the back door replaced today which is the alarm exit door. The joiner has refitted the sensor but there is now the following fault displayed -
"Back door Wirls Supervn F1"
Does some kind soul know what the problem is and how to fix it?
Thanks
