Honeywell Rth221b compatibility with Nest GA01334

[harshadkotw]

Hi,

We bought a nest thermostat to replace our old Honeywell programmable thermostat. I am not sure if it's compatible though because after checking in the tool it shows that we may need Nest learning thermostat. I wanted to know for sure if we can replace our current set up with the snow (GA01334) model.

Current wires are G,Y, W, R, Rc.

If it's compatible, what would be the right configuration?

Here's is our current setup

 

[Houptee]

Looks like you have 2 separate systems, a heating system and a AC system is that correct?

What kind of heating system is this? Hot water boiler with baseboard heaters or radiators or hot air heat?

Because you have 2 R wires Rh (heat power) and Rc (cooling power for the AC) then the only Nest you can use is the Learning model.

The other issue will be there is no C wire so you might have problems unless you run a new 5 conductor thermostat cable to the AC unit and connect a C wire to the AC unit and the Nest (use the blue wire for C is the standard color).

If the AC is in the attic you can probably buy a roll of 5 conductor cable at any big box store and tie the old wire to the new cable by stripping the insulation off and twist them together securely then gently pull it up into the attic (or down from the attic to the Nest.)

[harshadkotw]

Thanks! We checked with a local expert who said the same thing. For now I have put it off until we replace our HVAC system.

[Jake]

Hey there,

Thanks for the help Houptee.

I wanted to check in and see if you managed to see Houptee's post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.

Best regards,
Jake

[Jake]

Hey there,

I wanted to check in and see if you are still in need of any help. Please let me know, as I would be happy to assist, and answer any questions you may have.

Best regards,
Jake

[harshadkotw]

Thanks, we felt it was too complex for us to do this for now. We will reconsider after we replace our HVAC system.

[EmersonB]

Hi everyone,

@harshadkotw thanks for getting back to us and for updating us with your decision. Let us know if you have more questions in mind.

I appreciate the help, Houptee and Jake.

Regards,
Emerson

[aatienza]

Hey there,

Since this thread hasn't had activity in a while, we're going to close it to keep content fresh. Feel free to submit another post, and provide as many details as possible so that others can lend a hand.

Thanks,

Archie