Furnace ON activates A/C when on shore power

[Namutony]

A curious glitch in the operation of our furnace: when I turn on the furnace, it starts and runs fine, but if we're connected to shore power, within a minute or less the A/C also switches on. So we have cold air thru the ceiling A/C outlets and warm air thru the floor level furnace outlets, competing with each other.

I suspect the controller or IC board/s for furnace or A/C may have been affected by low voltage during a recent 3 month stay in Mexico without benefit of an inline voltage regulator (I have subsequently purchased one that will accompany the RV everywhere).

Is there a reset sequence for the electronics?

[A32Deuce]

Select fan on your thermostat and put it on AU for automatic. Now Try the heat. AC fan should be off.

[5picker]

Take A32Deuce's advice, it will stop.

It is not an issue or something wrong.

It is an option provided by the manmanufacturer.
Hot air rises. The A/C fan distributes that air.
The compressor doesn't run, only the fan.

Many folks like the option, others don't but it's your choice.

[CedarCreekWoody]

The reason it blows only on shore power is it is 120 volts. The furnace fan is 12 volt.

[Namutony]

Thanks everyone, especially A32deuce and 5picker ! I followed the thermostat setting that A32deuce suggested, and now it does what's expected. Happily not a fault ! Happy social distancing everyone ... let's hope we can get back to our favourite lifestyle sooner than later!

[A32Deuce]

I like that feature of running the fan at night as a noise blocker when at a noisey overnight stop on winter trips. Summer/warm weather, the A/C is on. Glad it worked for you.