Our HVAC setup includes a humidifier, but the control board seems to activate it only when the fan is on without heat/cool. Here's how I got to that conclusion:
- I hooked up my multimeter to the transformer that connects to the wires going to the humidistat, on the 24V side, so I can see whether it is getting a signal
- When I use the thermostat to switch the heat on (which includes the fan), there's no signal to the humidifier
- When I use the thermostat to switch on only the fan, without heating or cooling, there's a signal to the humidifier and it works
I'm thinking this isn't right, but correct me if I'm wrong. Can anyone help me troubleshoot why it won't come on when the heater is on?
We moved in earlier this year and haven't used the humidifier until now. We don't know anything about who installed it, but there was a spare solenoid laying around, so it's my guess that the last owners also tried to fix it. We fixed that portion though and now it does do its job when the control board actually sends a signal.