Just returned from a church with 2 new Mears line voltage (120v)thermostats. The T-stats are controlling cabinet unit heater fans with aqua-stat at coil for fan deactivation at low temperature only. They have the same problem I see above. Fans run at T-stat call, but with a set point of 65 degrees reached, fans do not shut off until 45 degrees. Stumbled on to this site trying to find web site for Mears. Anybody got one? I did not install T-stats and there are no schematics at site.

I separated your question from the old thread you had piggybacked onto.

A 120 volt stat is nothing more than a single pole switch, two wires, one line and one load.

The stat will close when temp drops below setting, and open when it rises above setting.

Based on very little detail, I would think the aqua-stat that controls the fan only needs to be adjusted.


Best you can do to get better advice is to investigate how this cabinet heater is wired, sketch out the diagram, and post it here so we can see what you have.