AC compressor turns on instead furnace

[kevin80]

My AC is turning on when I select the heat function. 

When using the Cool function, my AC has worked all summer. 

I tried both heat pump off and on and that makes no difference even though I don’t have a heat pump. 

If I use my old thermostat, my furnace turns on with heat. 

Any suggestions?

[CoolingWizard]

Kevin80,

we need more information to assist you better.   Your Equipment configuration is not correct.  Your equipment is an Air Conditioner, Forced Air Heating.  You should have a wires on Rc, C, Y, W1, G.   Rc is Power in to the thermostat. The C is the Power Common to the thermostat.  The Y is the AC Compressor for cooling, the W1 is going to your furnace to activate heating.  And the G wire turns on your blower.  

when you initially installed your nest thermostat and you performed the system test at the end of the configuration did the heating work properly then?  

Wake up the Nest thermostat, rotate dial to Menu and select, then rotate the dial to EQUIPMENT and select, it will show you the current detected wires.  Write them down and tell me which ones are seen by the nest. 

Ken, AC Cooling Wizard

[kevin80]

Hi Ken! Thanks for the response. 

This worked last winter and the only thing that I have done with it the Nest was a factory reset awhile back. This is the first time trying heat after that. 

It shows:

Y-C-W-G-R-*OB

Thanks

Kevin

[CoolingWizard · Accepted solution]

Your original message stated you do not have a Heat Pump. If there is no heat pump there should not be a wire on O/B. That wire is for Heat Pump reversing valve control.  Make sure your equipment type states “conventional” and Gas Forced Air.  

Ken, The AC Cooling Wizard 

[kevin80]

I disconnected the wire and updated the thermostat and I have heat again!

Thank you. 

[aatienza]

Hey folks,

kevin80, we're glad to hear that you've got it working by following CoolingWizard's suggestion. Let us know if you have other questions as I'll be locking the thread after 24 hours.
 

Thanks,

Archie