Zone valve or Switch?

phnick

Good morning and thanks in advance for help!

I am troubleshooting a zone of heat that works inconsistently. Baseboard heat. All the other zones work flawlessly.

I call for heat, sometimes in works, sometimes it doesn't fire the boiler. I checked:
1. Thermostat is good, tried two of them, checked wiring, getting 24v
2. Zone valve is getting 24v, checked the wires to switch and motor
3. If I press the switch manually the boiler comes on right away
4. Sometimes the paddle moves and ignites, sometimes it does not.

My question, do I just replace the motor, or whole assembly?

Thanks so much!! Nick

Zman

Replace the whole thing. Sometimes the switch is bad, sometimes the motor won't open that valve all the way.
As long as you are there, confirm that the valve cycles freely with the head removed and make sure the transformer is sized correctly.

Aluvaboy

Zman said:

Replace the whole thing. Sometimes the switch is bad, sometimes the motor won't open that valve all the way.
As long as you are there, confirm that the valve cycles freely with the head removed and make sure the transformer is sized correctly.

I just replaced three zone valves. Honeywell Model #V8043E1012. The price of the whole assembly vs the power head is pretty much the same. Only a $6.00 difference from Supply house. Although I bought the whole assembly, I only swapped out the power head, O ring and the ball valve. The old ball valve was sticking. Now everything is working fine in my gas boiler system.

phnick

Folks - thank you for your responses!

Let me ask you this, do you think weather plays a major role in how a boiler functions? The problematic zone was fine until the temp hit 0, and it's been in the low teens all week. BUT, now that it's back in the 30's, the problem hasn't been noticeable. In other words, when the zone calls for heat the boiler works.

It doesn't make sense because the zone valve and boiler are in a warm room, and other zones are working.

Thanks!!