Hello,

I am having an issue with my Air Handler. I just had a yearly service done on the unit both Heat Pump and Air Handler. It was recommended that I replace the thermostat, which I did with a Honeywell and still have the same problems. I'm sure I have it wired correctly, even confirming it with the company.

Problem - The unit fan will run in the On position, but will not run in the Auto position. The Air Handler coils freeze up and I have to mess with it to get it to work. Any help would be appreciated.

Be a little helpful. Post a link to the instruction manual or a model number of the tstat.

Check to make sure the tstat is configured for "The thermostat controls the fan (G terminal).

You didn't mention if this happens in AC, Heat modes or both modes.

Because it works in ON and not Auto, I'm suspecting a configuration problem in the stat.