Boiler Heating Question

[sroxberg]

I have hot water registers in my house and have had a recent problem.

The heat in one zone was running full bore the other day and the thermostat was set to cool which should have done nothing on that zone. It is for heat only.

I turned off the thermostat, reset it, replaced the batteries, and then removed it from the wall. With the unit removed from the wall it still appeared to be pumping out heat so I'm guessing that the valve/relay in by the boiler is defective.

That said a week ago a plumber was working on that zone and removed one of the heat registers and raised it one inch so that I could install at 3\4" hardwood floor. Is it possible that his work caused the problem with the relay? I don't know if or how they got any air out of the system since they cut the line and drained that area.

I know little to nothing about the boiler and heat.

Does it sound correct or possible that the relay could be calling for heat on it's own?

[Snipe Hunter]

Calling Blackhat. Where are you Blackhat?

[blackhat]

My apologies, I missed this thread last night. A handful of possibilities come to mind based on what you've said. 


   The plumber put the zone valve in the manually open position to leak check and purge air from it and then missed returning it to normal operation. Check if the valve has a switch or lever to lock it open. 

   The thermostat wire ate a nail or some how got pinched and is shorted. Effectively it would be stuck "on". Disconnect the wire from that stat downstairs where it connects to whatever control system you have. If the valve closes, trace the stat wire to find the problem. 

  There is a control failure. Disconnect the wires from the zone valve and see if it closes. I would need a lot more info on your control package to troubleshoot that further. If the zone continues to heat, it's possible the valve is fouled and leaking through. That would require removal of the valve and cleaning or replacing it. 

The above assumes your system uses normally closed valves. Probably 90% or more residential systems do. If you have normally closed valves it's all different. Let me know the make and model of the zone valves and I can check which they.