Nest Wiring Configuration

[leatherneck]

How do I wire this current configuration into a Nest Learning Thermostat?

[David_K · Accepted solution]

Y1 -> Y
G -> G
RH -> RH (don't connect the jumper wire between RC and RH, Nest thermostats have an internal jumper wire).
Y2 -> Y2
O/B -> O/B
C -> C
W/E -> E

As you have an O/B wire, I assume that means you have a heat pump, which means your W/E connection should be wired to E.

[leatherneck]

Thanks!  I actually had a HVAC guy come out because I also had a bad fuse. He connected like your answer except he connected to Rc vice Rh. Nest quit working at 3am and it said Rc wasn’t connected, but it came back on at 4:30am and seems to be ok 3 hours later.   Your thoughts on Rc vs Rh?

[David_K]

I'd connect it to RH if it was connected to RH on your previous system, but I'm not a HVAC professional. 

[leatherneck]

We’re conversing about a HVAC question. What’s your expertise, if not that?