Nest thermostat compatibility help- Emerson thermostat/Gas furnace

[NestHelp3]

Looking for help on hooking up a Nest Thermostat.

Currently have an old Amana GCE502 furnace (no A/C) with this Emerson UP500W Thermostat.

I have a red Rc wire, Blue O/B wire, a green G, and a white W/E wire.

I assume for the Nest thermostat, I go green wire to G, the white W/E wire to W1.

2 questions: I don't have a heat pump outside, do I need to connect the O/B wire at all? Not sure why that is even connected. And Do I go red wire to Rc like my old thermostat, or go to the Rh slot on the Nest? Again not sure why this heating only setup is connected to Rc.

[HVAC]

If it’s gas heating only not sure why they would connect o/b wires. Check at furnace control if it’s connected to anything if not you’d need to use it as a C connection on the nest & at heater control board. You’d connect red wire to Rh or just R on nest depending on which model you have. Green does go to G and white to W/W1 hope that helps. Good luck. 

[zoeuvre]

Hi folks,

@NestHelp3, thanks for reaching out to us, and I'm sorry to hear about the situation. I want to check and see if you are still in need of any help. If so, please be informed that your thermostat wires are compatible with any of our Nest Thermostat and should be wired to the thermostat base as follows: 

• White wire to W or W1
• Green wire to G
• Blue wire to OB or *OB
• Red wire to R or RC or RH

Also, here's a guide for the installation and setup of a Nest Thermostat. 

Let us know if you have any other questions. We're happy to help. 

I appreciate your help, @HVAC. 

Best,

Zoe