I have an HAI Omnistat controlling a Trane XE90 and an Aprilaire Humidifier.
Problem I am having is the thermostat only has a single wire for Humidifier control which does indeed activate the solenoid on the humidifier when the humidity is too low. The problem is that it sometimes calls for humidity even if there is no call for heat. I thought the thermostat would call for both Fan and Humidifier in this case; but it only calls for the humidifier. So the humidifier runs without a fan which is useless.
I called the vendor and they said this was normal operation and something would have to be rigged up externally.
My initial thought was to strap the G (FAN) and humidifier wires together but I think that will also kick in the humidifier in the case there the Tstat calls for FAN and doesn't need humidity.
Any ideas on how to accomplish this?
The manual is here:
Thanks in advance