Nest Thermostat AC works but heating doesn't

[Minnie2]

Technician that installed our NEST in October just came to my home after we told him the Heateris not working. AC works great.   We have 2 NEST Thermostats (upstairs/downstairs).  We trouble shot the products.  Checked settings.  He tried a different thermostat unit and the heating unit works.  Do we have two defective NEST thermostats?  What are the odds....or is our heater incompatible?.....Our heater is a RAAD Silhouette II and it is working great.  

[jb76]

Hi - Please share your wiring setup for the thermostats - it should be the following to both Nests:

W - Furnace/heat cobtrol

Rh (Power. from furnace)

Y1 ( AC control)

G ( Unconditioned air/fan on furnace)

C ( Common to charge thermostat - usually a blue wire but can be different color depending on how old your furnace/AC is).

J

[Minnie2]

The tech is here and he states that the wiring set up is correct (as listed above)

[jb76]

Ok - removing those 2 other Nest thermostats leaving just this one that cannot turn on the heat - can the technician explain what/where the W wire to control the furnace is going to in the furnace control board? Please reply with the wire connections to this “problem” thermostat. Thanks!

Also, please provide the power level to the Nest (under Settings—> Technical—> Power). If it doesn’t show a min. of 3.85 V - it will not be able to communicate to the furnace/AC.

J

[Minnie2]

Power is good per the device.  The tech spoke with Nest Support and they determined a bad port for G and a general failure on the second device.  They are replacing both devices per warranty.  

[jb76]

Hi - thank you for sharing that...glad that the issues could be identified.

[Markjosephp]

Hello everyone,

I'm dropping by to make sure everything is covered here.

Thanks for helping out with the wiring configuration, @jb76.

@Minnie2, it sounds like you've been through quite a troubleshooting journey with your Nest Thermostats. It's unfortunate that you've encountered issues with both units, but it's great that the technician was able to identify the issue and work with Nest Support to resolve it under warranty. Having both thermostats replaced should address the problems you've experienced, and it's good to know that your heating unit is compatible and in good working condition. 

If you have any further questions or concerns during the replacement process, feel free to reach out. Hopefully, with the new Nest Thermostats, you'll have a smooth and trouble-free experience with both your heating and cooling systems. Stay warm!


Best regards,
Mark