Nest thermostat

[Bl10]

Hi. I have a new nest thermostat 3rd gen. I no longer have control over the fan. No fan option available. I have a 4 wire setup. Black wire to Y1,  white wire to W1 , green wire to C , red wire to RH.

The old thermostat was a Honeywell.At the furnace a Honeywell a THP904 wire adapter with 5 wires go into from furnace and 4 out to the thermostat.

Furnace is a 2 stage with air conditioner. Had control of fan with old thermostat. How do I solve this.

[virnab]

Hi Bl10,

Thanks for reaching out to the community.

I'm sorry to hear that you're no longer able to control your fan after installing your new Nest Learning Thermostat (3rd gen). I understand how concerning it is to lose a feature that you had with your old thermostat. Thank you for providing the detailed information about your wiring and the Honeywell adapter. It is my pleasure to assist you with this concern.

Based on the information you provided, I recommend you get in touch with a Nest Pro Technician to check the installation of your thermostat. It is necessary to verify the position of the C wire and check the wiring between your thermostat and the HVAC system.

If you have more questions or need more assistance with your Google Nest products, do not hesitate to contact us.

Best regards,

Virna

[Patrick_Caezza · Accepted solution]

@Bl10 

Post a picture of the original thermostat's wiring here.

[Bl10]

Sorry but I see no way to attach a photo 

[Bl10]

 just figured out how to attach

[Bl10]

 

[Bl10]

This is what the thermostat is wired to at the firnace

[Patrick_Caezza]

@Bl10 

You'll need to replace the Honeywell device at the furnace with the Nest Power Connector. Although they do the same thing, they are not compatible.

Just follow the wiring instruction.

[Bl10]

Can I use the Meross wire adapter https://www.amazon.ca/meross-Adapter-Smart-Thermostat-Required/dp/B0DYH2ZGZY