I have a 23 year old Megaflo heating and hot water system powered by the original Thermecon oil boiler. One of the most common kinds of faults I get with this system is the continually running circulating pump.
The upstairs and downstairs CH are separate circuits each with their own Danfoss motorised valves. I end up changing these every 3 - 4 years. The hot water is controlled by a Honeywell motorised valve which, AFAIK, has never been replaced.
Now the pump is running when the system is set to off. When the system is on, the Honeywell valve opens and closes as expected (when hot water is run, the valve opens, then closes when water temperature attained). The CH valves are also operating as expected: ie, thermostat calls for heat, the valve opens etc. But whether the microswitches are working, is another question.
My question is: what procedure should I follow to identify the reason for the running pump?
The upstairs and downstairs CH are separate circuits each with their own Danfoss motorised valves. I end up changing these every 3 - 4 years. The hot water is controlled by a Honeywell motorised valve which, AFAIK, has never been replaced.
Now the pump is running when the system is set to off. When the system is on, the Honeywell valve opens and closes as expected (when hot water is run, the valve opens, then closes when water temperature attained). The CH valves are also operating as expected: ie, thermostat calls for heat, the valve opens etc. But whether the microswitches are working, is another question.
My question is: what procedure should I follow to identify the reason for the running pump?
