Thanks. Am I right in assuming that, as there is no hot water when the problem occurs, it is the micro switch on the CH?
I thought it was S plan like the diagram attached as there are 2 no. 2 port valves.
I have an Ideal boiler (ancient) with a Honeywell ST9420c control and one thermostat. I believe it is an S type system from what I have read.
I changed the control from an old Honeywell a month or so ago. The system seemed to be running as expected.
Now, the system keeps running when I don't...
Seems I have a very similar system to Apnomis and I have found this thread very helpful as I am looking to do this same upgrade. So, thanks for all who have provided comments.
Quick question. Would it be worth putting Drayton RT212 TRV thermostatic valves on the radiators upstairs? I'll be...