cancel
Showing results for 
Search instead for 
Did you mean: 
Replies are disabled for this topic. Start a new one or visit our Help Center.

Nest Learning Thermostat not turning on Heat Pump and causing clicking noises

zprimus
Community Member

I installed the Nest Learning Thermostat a couple months ago and it was working fine, but I had to replace my old indoor and outdoor unit due to failure, mold, etc. My new outside unit is a heat pump from Ruud. It came packaged with a HoneywellHome T6 Pro thermostat and works correctly with it. When I try to heat with the Nest, the heat pump tries to turn on but makes a constant clicking noise and doesn't spin the fan.

 

The wiring for both thermostats is below (Honeywell - Nest)

Y - Y1

G - G

C - C

O/B - O/B

AUX/W2 - AUX/W2

R (internal jumper to Rc) - Rh (internal jumper to Rc)

The new system has a B configuration for the O/B valve, which is set on both thermostats.

 

I'm trying to understand why it works with the honeywell and not the nest, when I believe they're both wired and configured the same.

4 REPLIES 4

Ryan_G
Community Specialist
Community Specialist

Hi zprimus,

 

Thanks for reaching out and we're sorry for the delay.

 

Let's try the following to further isolate the issue:

  • Go to settings > equipment then select the right heat type and source.
  • Change the O/B orientation. Go to settings > equipment > select continue then continue and select heat pump
  • Check all the wire and make sure they are all properly inserted

Let me know how it goes.

 

Regards,

Ryan

zprimus
Community Member

Yes, I checked all of this. Flipping the O/B orientation either way just blows cool air out when I try to heat. On the B configuration (which is the correct orientation) the heat pump just makes a constant clicking noise. The wiring is as described above, and this honeywell thermostat works with almost identical wiring. I've had "heat pump" selected as the equipment during all of this as well.

zprimus
Community Member

Also the heat type and source are "forced-air" and "electric". The thermostat can see all of the wires connected since it displays them on the screen after I connect them. I don't know what the voltage should be for each terminal, but I could check that with my multimeter if I knew that info. I'm not sure if that's a value decided by the thermostat or the equipment.

Ryan_G
Community Specialist
Community Specialist

Hey folks,

 

Thanks for visiting the Google Nest Community. 

 

Since this thread hasn't had activity in a while, we're going to close it to keep content fresh.

If you have additional questions, feel free to submit another post and provide as many details as possible so that others can lend a hand. 

 

Hope this helps!

 

Kind regards,

Ryan