I have an alpha he sy25 boiler which yesterday started running continuously despite all program's manually switched to off.
I have changed the Drayton ZA5 zone control valve head and also the Honeywell two port valve head but it continues to run.
All program's are switched to off and the rads are all red hot. Currently the only way that I can get the boiler & pump to shut off is the isolate the boiler from the spur.
I have noticed though that I have been given a Honeywell valve head for a three port valve and not a two port valve. Would it be reasonable to suggest that this is currently the cause and that the old Honeywell valve head was faulty as I don't want to have to return this, pay a 25% restocking charge at plumb base and then purchase the correct one if it is unlikely to be the cause.
Help!!
I have changed the Drayton ZA5 zone control valve head and also the Honeywell two port valve head but it continues to run.
All program's are switched to off and the rads are all red hot. Currently the only way that I can get the boiler & pump to shut off is the isolate the boiler from the spur.
I have noticed though that I have been given a Honeywell valve head for a three port valve and not a two port valve. Would it be reasonable to suggest that this is currently the cause and that the old Honeywell valve head was faulty as I don't want to have to return this, pay a 25% restocking charge at plumb base and then purchase the correct one if it is unlikely to be the cause.
Help!!