Hi there. I installed my thermostats this Summer and it’s worked great. But now that we’ve started using heat, we noticed the outside A/C fan turns on whenever the heat turns on. Is this normal? Have we wired it wrong. I’ve attached themostat wiring photos for before, after, and the furnace.
during setup, did you tell it you have a heat pump?
I don’t see anything with your wiring that would cause the compressor to kick on if you had selected a non heat pump system.
For right now, without having to deal with resetting your thermostat, you could just disconnect the y wire. You will need to reconnect it when you want to cool again.
Honestly, I don’t know. I suppose that the question happens in the original setup? I guess I’d have to do a reset to be sure.
Upon further research, if you do choose heat pump apparently a “Swap Heat and Cool” option appears in advanced settings. I do not see that in mine. So it seems I chose no heat pump.
What if I have a heat pump? How do I know?
You don’t have a heat pump. You would have a B or O wire if you actually had a heat pump.
Did you by any chance tell it that you did not have a C wire? It might be trying to use the C adapter which could potentially turn on the compressor when you don’t have a C adapter installed.
The easiest fix / test right now would be to disconnect the “Y” wire at the thermostat.
If the compressor still runs during heat with the “Y” wire disconnected at the thermostat, then you have an issue with your furnace control board, or the wires in your wall (mice can chew through insulation and short wires together), or your A/C contactor, not your thermostat.
If this is the case, then you can eliminate the wires as being the problem by disconnecting the yellow “Y” wire at the furnace.
If the compressor still runs during heat with the Yellow “Y” wire disconnected at both the furnace and the thermostat, then your furnace control board or your A/C contactor is bad.
You can eliminate the furnace control board as the problem by removing the red “Y” wire from your furnace control board. If the compressor still runs, then the A/C contactor is stuck down and you need to call a tech out to have it replaced. You should pull the A/C disconnect to avoid damaging your compressor until you can get it replaced if this is the case.
If the compressor stops running with the red “Y” wire removed from the furnace board, then you will need to call a tech out to have the furnace board replaced.
I’m sure I set the thermostat up WITH a C wire.
I agree. There is no indication that my A/C is a heat pump either. I’ve attached a photo of the model, although it’s not conclusive. But yeah, I’m sure you are right.
I am testing another setting in the Advanced Settings. For some reason, I had “Fan Activation Delay” set to “15 seconds.” Last night I switched it back to “By Furnace.” It seems like the A/C is not kicking on now, but I need to confirm.
If your compressor is turning on when the fan is being turned on, then it is likely that it thinks it has a C-adapter installed.
So this is what I’ve determined by research and talking with my neighbors that have the same HVAC system. I do have and am set up with a C wire, both physically and in the app. I do not have a heat pump with my A/C.
It seems to have to do with the Advanced Settings in the Wyze app. When I have “Fan Activation Delay” set to “15-60 seconds,” the A/C fan will run when the furnace runs. I’ve determined this is the wrong setting for my system and I have switched it back to “By Furnace.”
Now the A/C fan does not kick on when the furnace runs, and the furnace has it’s own lower power fan that moves air. When running the A/C for cool, the A/C fan DOES turn on as expected.
Thanks all for the help.
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