Nest intermittent heat signal to furnace

[pjmcgnns]

Furnace loses thermostat heat signal intermittently during startup and chatters the gas valve and auxiliary combustion air intake system. Furnace often then fails to fire and then short cycles to recover. C wire is installed. Single zone gas hot air heat and AC. 

[RenzJ]

Hi pjmcgnns,

Thanks for posting here in the Google Nest Community forum.

We're sorry for any trouble this may have caused you. I wanted to check this further for you. Let’s gather the power reading of your Nest Thermostat.

For the Nest Learning Thermostat and Nest Thermostat E:

1. Press the thermostat ring to bring up the Quick View menu.
2. Turn the ring to Settings and press to select.
3. Turn the ring to Technical Info and press to select.

For the Nest Thermostat 2020:

1. Tap the touch bar to bring up the menu view.
2. Slide your finger down to Settings, then tap to select.
3. Slide your finger to Equipment > Power Info.

Also, send us a couple more details, like the make and model of your HVAC, a photo of your current wiring on the Nest Thermostat, and the wiring on the control board.

I look forward to your response.

Regards,

Renz

[pjmcgnns]

Power is 3.78volts. Heater Controller Conquest 90 high efficiency gas hot air furnace 1 stage. How do I add pictures of the wiring?

[RenzJ]

Hello pjmcgnns,

Thanks for the update. Have you also gotten the VOC, VIN, and LIN details when you run the power reading? To attach the image, you can go to this link: Google Nest Community Forum. Hit reply on the thread, and you'll see a camera icon or three horizontal lines to expand the toolbar, where you can click the camera icon and send your image.

Keep us posted.

Best,

Renz

[pjmcgnns]

There is no camera icon when I expand the 3 dots

Battery:3.931

VOC:36.95

VIN:36.95

LIN:200 ma (c)