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Nest thermostat: no option for Emergency Heat

billywilde
Community Member

My landlord installed a new HVAC system this past year and I installed a Nest thermostat. It has worked well during the warm months with cooling my home. My landlord informed me that although the system was wired as a heat pump, it is not an actual heat pump system. For heat, I have been instructed to use the emergency heat setting. 

My old thermostat has a setting for emergency heat and it works fine. My old thermostat has C, B, R, G, Y wires plus White W/E & W2 wires jumped. All colors transferred to the Nest except just a single W for the white wire. After setup the Nest doesn't give me a choice to select Emergency or Auxiliary heat. And when it is set to heat, there is no warm air from the system.

I know instructions say not to use jumpers but I'm wondering if it would work if I jumped the white wire to the OB* connector. Has anyone else had this same situation and if so, what did you do to solve it? 

1 Recommended Answer

billywilde
Community Member

It turns out my wiring was fine how it was done. I contacted the HVAC installer and he informed me my unit did not have emergency heat. I set the thermostat to heat and let it run for a while. Voilá! Heat comes out.

I apologize for not reporting my findings. Perhaps you can contact an installer and they can identify the correct setup for you.

View Recommended Answer in original post

8 REPLIES 8

Ryan_G
Community Specialist
Community Specialist

Hey billywilde,

 

Thank you for posting here and we're sorry to hear about the situation. 

It's best to check your wiring and what type of Nest Thermostat you're using. You could reply to this thread with a photo of your current wiring and we'll start from there.

 

I hope to hear from you soon.

 

Regards,

Ryan

 

Hi Ryan,

My Nest thermostat is a basic model. I’ve attached a photo of the back which shows the QR code. Another photo shows my wiring, plus another is the back of my old thermostat. Note that my old thermostat has a jumper between W/E and W2 connectors. I’m thinking this is why my old thermostat must be set to emergency heat for single stage heating.

Do you think another Nest model may work better for me?

Thank you in advance.

Billy20220201_091404.jpg20220201_091433.jpg20220201_091505.jpg

Ryan_G
Community Specialist
Community Specialist

Hey billywilde,

 

Thanks for the update.

If I can see it correctly from the second photo, you also have an unused orange wire. It is unusual that this wire is not connected to your thermostat. An orange wire is commonly used when a system is a heat pump. Let's try to use the orange wire and connect it to the OB terminal and leave the W1 (white wire) to it's terminal then go to settings > equipment and select the right heat type and source. 

 

Let me know how it goes. 

 

Regards,

Ryan

hello I'm having the same problem did you ever get a solution?

Idd
Community Member

I have this exact problem. My HVAC system has a heat pump and an emergency heat feature for when temperatures are extremely low. I bought a nest thermostat that has only six wiring slots. My old thermostat had six slots and a jumper. Now that I'm in the midddle of an arctic blast in the southwest (Texas) with temperatures in the mid 20s, it turns out my heat pump is insufficient but my emergency heat will not heat up the house despite the thermostat showing 'emergency heat on'. I have included pictures of my wiring. Please let me know what I need to make my emergency heat work again. 

Original wiring:

Screenshot_2023-02-01-11-23-42-16_92460851df6f172a4592fca41cc2d2e6.jpg

Current wiring:

IMG_20230201_112224.jpg

I currently have thermostat below installed:

IMG_20230201_112950.jpgThank you in advance for your help. 

harveyg007
Community Member

Same problem here. 

Jpbean
Community Member

Same problem here, only I have a wire in the *OB slot.  Wires I have connected are:

Y-W-G-R-*OB

PLEASE SHARE SOLUTION??!!

billywilde
Community Member

It turns out my wiring was fine how it was done. I contacted the HVAC installer and he informed me my unit did not have emergency heat. I set the thermostat to heat and let it run for a while. Voilá! Heat comes out.

I apologize for not reporting my findings. Perhaps you can contact an installer and they can identify the correct setup for you.