I have noticed that one zone in my 4 zone system is over-heating. The thermostat is set for 65 and I recently discovered that the room is running about 75 or 80. Thermostat appears to be OK.

Opened the Zone Valve cover and one time discovered that it appeared to be 1/2 way between the open and closed position - a little push on the lever and it retracted to "closed". Another time the burner was running far too often and I found the suspect Zone valve in the fully ON position (up against the switch) despite the thermostat being satisfied (room 10 degrees overtemp). A couple of raps on the zone valve with a broom handle caused the syncro to de-trigger and release.

Is this a problem with the entire Zone Valve, or a symptom of a bad syncro motor?

3 zones are on one pump (the suspect zone is one of these) and the 4th zone is on it's own pump. I believe this is why, when the zone valve is not fully closed that whenever any of the other two zones on that pump call for heat, the suspect zone gets heat despite the thermostat being satisfied. As for the times when the burner goes on and on.... well that is obvious... with the switch pushed "ON", the burner will go until the temp upper limit is reached, the pump keeps circulating until the lower limit is achieved, then the burner comes back on.

All other zones appear to be working just fine. I just don't know if a motor replacement will fix this, or if the valve is sticking, or what. I don't understand why a rap on the Zone Valve causes it to release and allow the spring to pull the valve shut. It almost seems as if the valve itself is sticking. Does the motor ONLY OPEN and HOLD OPEN the valve, then when power is released the spring is responsible for closing the valve? If so then it must be a mechanical problem.

This system also incorporates one of the new Beckett Heat Managers - which dynamically calculates the heat load of the house and holds off the burner when it figures that the latent boiler temp is high enough to handle a call for heat. This cuts down on the number of burner cycles - a great concept but I've had to replace the unit 2 times due to "bugs" in the first 2 units. This latest version has been working well this heating season.

Thanks in advance for your help,

Andy

 

The problem you are having is a typical motor problem. The motors are readilly available & quite easy to replace.

 

Thanks Grady.

I read here elsewhere that the procedure is: shut off system, lock valve in OPEN with lever, remove and replace motor with single screw and power leads, release lock and re-energize system. I'll just google for a source for the motor unless someone knows a reliable source.

Andy

 

Your local plumbing supply has them

 

Check out www.patriot-supply.com also.