I have a gas fired hot water boiler with three zones ( Taco zone valves). Each zone is controlled by a thermostat.
On one of my zones, the thermostat calls for heating but the boiler does not fire. I changed the thermostat with the other zones and they work fine. It is just this zone.
When this zone calls for heat, the Taco zone valve show no resistance in the lever and does not fire the boiler. The only way that this zone gets heat is when one of the other zones calls for heat, and the t'sat set point is above the space temperature then the valve is open and hot water flows through it.
What do you guys think is the problem? Please help.
the fastest way to solve this would be for you to go on yahoo and type in taco zone valve wiring there are numerous schematics etc, make sure your wiring is correct and connections tight. Be careful disconnecting the 3 wire actuators, before taking off of the valve body disconnect the 24volts for about 5 minutes These old valves had a heat motor read caution notes