Trane 4YCY4042B 1st Stage Heating Not Working

[aka_rob]

Hello!

I just installed a Nest Learning Thermostat and the 1st stage heating is not working. The nest shows that it's on, but there is nothing coming from the vents. We have a Trane 4YCY4042B1096BA (if that means anything).

2nd stage works like a charm. Any suggestions?

Here is the previous wiring and what the Nest is linked up to:

[aka_rob]

Also worth pointing out that when the thermostat is saying stage 1 is running, there is no sound of gas running at the meter (the unit is on the roof, can't tell if it's running or not otherwise).

[Jhonleanmel]

Hi aka_rob,

I'm sorry to hear that you're still having an issue with your Nest Learning Thermostat. We'd like to take a deeper look into this — could you fill out this form and let us know once you're done?

Thanks,
Mel

[aka_rob]

Thanks Mel! I've filled out the form. I appreciate the reply!

[EdwardT]

Hi aka_rob,

We got your form — thanks for filling it out. Our team will reach out to you via email to further assist you. Also, please be advised that this thread will be locked after 24 hours.

Thanks,

Edward