I have a gas 3 zone hot water baseboard heat system in my home. The basement and 2nd floor systems work fine. I replaced the 1st floor zone control valve head because it would not close. Now it does not open and start the furnace every time the thermostat calls for heat. If I short out the thermostat connections with a jumpet wire at the valve until the valve opens and the furnace kicks on the zone valve will stay open and the furnace run until the temperature is reached. Once the valve opens and furnace is on I do not have to continue to hold the jumper wire on the terminals. Sometimes the furnace works when this thermostat calls for heat, sometimes not.
I am puzzled why I only have to short the terminals until the system starts and how to fix it. Honeywell t87f thermostat,
24 volts, mercury switch. Have I confused you enough?
Phil
I am puzzled why I only have to short the terminals until the system starts and how to fix it. Honeywell t87f thermostat,
24 volts, mercury switch. Have I confused you enough?
Phil