Thermostat - Aux Heat Control

I have a Dual Fuel Package Unit (Heat Pump/Gas Aux Heat).

I’m not sure I understand what makes the Aux Heat turn on.

I believe I read somewhere that the Heat Pump will run for 30 minutes and if it can’t increase the heat in your home, it will turn on the Aux Heat.
That’s too long!

I also believe I read somewhere that if there is more than a 5 degree difference that the Aux Heat will turn on.

I just installed this last September…
I’m concerned that my Heat Pump is going to be running too much.

So my question is… Is there a good way for me to control the Aux Heat?

I’m still hoping to get some information on this topic…

We are back in freezing weather again and it’s running the Heat Pump!
Eventually the Aux Heat comes on but it takes too long!
Surely this is an even worse problem for people further north!

What makes the Aux Heat come on?


I’m in a similar boat except I can’t tell if my aux comes in at all. I woke up with it 10degrees below my set point. Ended up manually turning aux on to warm my house up.

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From what I have been reading, there are two ways that the Wyze Thermostat controls the Aux & Emergency Heat. Aux Automatically or Emergency Manually.

If connected to the " W1 " lug on the thermostat, it will control the backup as Aux Heat Automatically and turn it on if the heat pump can’t achieve set temp (+ differential) within 30 minutes or if the temp delta between the measured temp and target set temp is +5°.

If connected to the " * " lug, it would operate the backup manually as Emergency Heat, but there are drawbacks to this mentioned :point_down: below:

If jumpered, it could theoretically be used in both situations, but would need to be tested to confirm.

But, both must be specifically designated when doing the wiring setup on install.

@speadie would be best to verify my understanding of this though as it was their post that brought me to this conclusion. Because the OP had electric EH, it may be different and Speadie is the expert here.

W1 would have it operate automatically, “*” has it operate when emergency heat is on. but the wyze’s implementation of emergency heat is rather poor, it appears to disable the thermostat’s temperature control and it’s just an on or off switch.

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So I have them designated backwards above. The W1 is the automatic timed Aux and the * is the emergency heat with the caveat that when activated in the app it disables the temp control until deactivated in the app?

From my understanding, yes. I don’t have a heat pump to test this with, but from helping numerous people with their setups, that’s what I’ve gleaned.


Thank you so much for the assist and all the expert help you provide here in the forum! You are a valuable asset to the team!

Editing above to make it accurate.


I really appreciate the feedback on this topic!

I’m a little concerned about changing the wiring…

I haven’t seen a control for manual Emergency Heat in the app. Is that something that appears in the app if you wire it for that?

Is there any chance Wyze will do something to improve automatic functionality? It’s a total waste to run the Heat Pump in freezing weather. I’m concerned about my Electric Bill!

I believe the Emergency Heat UI only appears after it is set up on install.

Here is a post w\ pics of of what it looks like in the app:


Thanks for adding to this topic!

You mentioned “manually turning aux on…”
How did you do that?
I’ve not seen that in the app…

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