Issue with new nest

[pigglywiggly23]

the original thermostat was an old Honeywell mercury round unit- 4 wires- red, green, yellow, black.

I installed a new nest using these wires, black wire into the W terminal- when the heat would turn on the fan would kick on but the furnace wouldn't, any thoughts? I've included pictures of the old Honeywell unit as well as the circuit board on the furnace.

[EdwardT]

Hi pigglywiggly23,

Thanks for reaching out. I'm sorry to hear that you're having an issue with your Nest Thermostat? I'd love to know more about this and I have a few questions:

• What type of Nest Thermostat do you have?
• How is your Nest Thermostat wired?
• Are you seeing a "delayed" message on the screen of your Nest Thermostat?
• What is the power reading of your Nest Thermostat? You can find this information by going to Settings > Technical Info > Power.

Thanks,

Edward

[EdwardT]

Hi pigglywiggly23,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[EdwardT]

Hi pigglywiggly23,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,

Edward