Wiring 4th gen heat only

[Krthomp33]

Looking for some help with my Nest 4th gen. I have an oil furnace with only 2 wires, that connect to the R & W terminals on our old Honeywell t-stat. When I connect the Nest following the instructions in the app, the level lights up indicating power, but once I connect the thermostat, the furnace starts short cycling. I even tried fully charging the nest to see if that helped. I then purchased the nest power connector, but with no C terminal to connect that to, there is no power going to the thermostat at all. 

Any ideas on how to proceed?

[EduardoN]

Hi @Krthomp33,

Thanks for reaching out to this community! I understand that you recently updated your Honeywell thermostat to a Nest Learning Thermostat (4th gen). It has two wires, R and W, and although you followed all the instructions, the furnace is starting in short intervals. It's good that you took the time to charge the thermostat and install a C-wire. I'm here to help!

At the moment, I'd like to ask you a few questions so I can give you the correct steps.

1. What other strange symptoms have you experienced since the problem started?
2. Are there any error messages? If so, what are they exactly?
3. When was the last maintenance check for your HVAC system?

I'd like you to check the following on your Nest Learning Thermostat (4th gen):

1. Check that the thermostat is installed correctly and that the wires are secure in the base.
2. Check the thermostat's power:
   1. Go to Settings > Check Equipment > Power info and send a photo of it.

Please feel free to share any additional details you think might be relevant.

Best regards,
Eduardo

[Krthomp33]

No error messages, the thermostat never changes from telling me to continue in the app. The furnace was just serviced. When I installed the power adapter, the level didn't light up as there is no place for me to install the C wire adapter as the furnace only has 2 connections.

I'll add pictures.

[Krthomp33]

 wiring at the furnace

[EduardoN]

Hi @Krthomp33,

Thank you very much for the update. Since your system only has two connectors and no C-wire terminal, the most appropriate way to get it installed and achieve the best results is to contact a professional for installation and service.

Keep me posted.

Best regards,
Eduardo