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Connect Nest to Extremely Old Furnace

codyecp
Community Member

Wondering if its even possible to use this Nest Thermostat with our VERY old furnace. We've ran a 3 wire down to the furnace which does have a fan and power terminal. I've been reading that the nest needs at least 3 things to function properly, which are basically heating control, common or constant power and fan (I think). So we bought a furnace 3 wire and ran it to the furnace, but I have no idea how/where to hook it up, if it's even possible. I've got 2 photos attached here. 1 photo is of the power terminal on the furnace and the other is the fan control (which has power running from the terminal on the furnace). We have a 2-way switch upstairs (separate from old thermostat) that when flipped, runs only the fan.

 

Any ideas would be much appreaciated!image_67213569.JPGimage_67199233.JPG

3 REPLIES 3

JenniferV
Community Specialist
Community Specialist

Hi codyecp,

 

Thanks for reaching out. It will be best that your furnace will be physically checked by a Nest Pro. You can use this link to locate a Nest Pro in your area. 

 

Regards,

Jennifer

EdwardT
Community Specialist
Community Specialist

Hi codyecp,

 

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

 

Thanks,

Edward

MelbaDT
Community Specialist
Community Specialist

Hi, 

 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

 

Best, 

Melba