A couple of days ago, my hydronic heating system stopped working. Thankfully, the boiler is still working though, so I still have hot water.
- When no one is using hot water, the boiler reports 0 GPM and the pipes are cold.
- I checked the circuit breaker panel, and none of the circuits have been tripped
- The pressure gauge above the expansion tank always shows 0.
- I think I only have one zone, so there is no zone valve.
- I don't think the two circulation pumps are running (I can't hear anything).
- The thermostat still responds to temperature changes (it goes up if I turn on the fireplace).
- FWIW, I can't see the wires that are supposed to go from the heating system up to the thermostat. Maybe it's hidden in some metal pipes.
I unscrewed the cap on the Webstone air separator a little, and only water came out (if air came out, it must have been very little). So I think that ruled out air being trapped. And as expected, nothing changed. Then, a few hours later, on a lark I changed the temperature on the thermostat, and magically it started working again! I'm really not sure why. If anyone has any ideas, please let me know. Oh, and the pressure gauge is still showing 0. Which also makes no sense.
Does anyone have any ideas what could be wrong?