Dual Fuel Install & Setup Confirmation for 2nd Gen Learning with Goodman GPDM3

[Aaron732]

Hello Nesters,

I've been using my 2nd generation Nest Learning Thermostat for many years with my old single-stage gas packaged unit, but it was time to replace the HVAC unit with something newer and better. I got a Goodman GPDM3 dual fuel (natural gas) packaged unit from a local contractor and the salesperson assured me it would work with the Nest, He also assured me that their install guys were familiar with the Nest and dual fuel.

They were not. After I talked them out of removing the Nest in favor of a dumb thermostat, I had to walk them through almost every step of the process. I think we made it work, but it's the middle of summer here and I want to be sure the setup is correct so that it actually engages the natural gas when the temperature drops below our set point (40 F, in Tennessee, so lots of very wet 30s days here in winter.) 

We sucessfully tested the A/C (working great now,) heat pump, and natural gas. My concern is that they put what appears to be the heat pump on W1 and the natural gas on W2 AUX. I want to be sure that it will leave the heat pump off at the set temp and switch over to the natural gas. This is a single stage compressor and there are not any electric heating coils as backup, just the heat pump and the natural gas burner. Is it a problem that the Nest is regarding the first alt heat as electric? Will it just bypas this and go to the gas on W2 as alt stage 2 when it hits 40 F?

Photos of my wires (techs had some dirty hands and got drywall all over after pulling new wire) and relevant setup screens are attached. If anyone needs other info to help, let me know and I'm happy to provide.

Thanks for your time and help!

[Markjosephp]

Hello Aaron732,

I'm sorry for the late response, and thanks for reaching out to the Google Nest Community Forum.

I appreciate you keeping up with the Nest Learning Thermostat 2nd generation despite having a new HVAC system. With its configuration, your Heat pump would be your main source of heat, and the auxiliary heat would only activate when the weather outside is too cold for the heat pump to work efficiently. So it'll only supplement the heat that your system generates through a heating element.

Please take a look at this article and let us know if you have more questions.

Regards,
Mark

[Aaron732]

Thanks, Mark. Looks like things are good--the article indicates that the dual fuel system should have W1 and W2/AUX wires and that my set temperature at 40 F should switch over to the natural gas system on W2/AUX when it dips below that. Fingers crossed! Nice to have someone in the community to help provide support when a contractor couldn't make good on their claims.

[Markjosephp]

Hey there,

We've got you! I understand that this can be confusing, but I hope you've got the answer you're looking for. If there’s anything else I can help you with, please let me know.

Best,
Mark

[Dan_A]

Hello again,

I wanted to follow up and see if you still needed help. Please let me know if you still have any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Kind regards,

Dan

[Aaron732]

Seems to be resolved, thank you!

[Markjosephp]

Hi Aaron732,

Sounds great! I'm glad to hear it was sorted out. It looks like we can consider this one complete, so I will lock the thread within 24 hours unless I can help out with anything else.

Best regards,
Mark