I have a pumped HW/CH system, with a three-way Drayton MA1 mid position valve controlling supply to HW tank and CH, with tank and room stats, that has been installed for several years. A month ago I had intermittent failures whereby the HW and CH fired even when the system was up to temperature, this seemed to be most likely to be caused by a short in the valve actuator causing the boiler to fire when it shouldn't. I replaced the valve actuator unit and all was fine for a month. However, it has happened again, although once the system is left to cool the problem goes away, and I've not been able to check the wiring outputs from the actuator when its actually failing.
Should I just replace the actuator again, or is there likely to be some other component that is causing the failure, and warrants further investigation??
Many Thanks
Phil
Should I just replace the actuator again, or is there likely to be some other component that is causing the failure, and warrants further investigation??
Many Thanks
Phil
