Thermostat not turning on boiler in one of the zones. Thermostat not the issue, it’s been replaced. Didn’t need to bleed the line but I did just to make sure. All other zones work fine. Also switches out the older taco valve to see if that was the issue—no dice. Not breaker issues either.

So I’m thinking some electrical connection issue somewhere in the heating system. The thermostat turns on the AC/Fan no problem.

The battle continues!