03-25-2023 02:54 PM
Hi I have an Honeywell thermostat I want to replace with a Nest. Is this compatible. Picture below. If so what are the best wire points. Please
Answered! Go to the Recommended Answer.
03-26-2023 01:40 PM
great and thanks for your response and patience. Is this the best you are referring to. Google Nest Smart Programmable WiFi Thermostat - Snow White G4CVZ. I appreciate the help
03-25-2023 03:17 PM
The Honeywell 900 series thermostats can operate between 24 to 230 V. So that thermostat can either be switching line voltage down to a furnace, or it can be simply operating at millivolts controlling a gas valve. It is not a conventional HVAC, where you would have 24 V AC coming in on our and being sent back on Y, W, G, O/B.. the only time I’ve ever seen these 900 series is over in Europe.
03-25-2023 06:39 PM
Hi thanks. This is a Honeywell CM907 thermostat. I should have mentioned it is for a gas boiler that runs my hydronic heating only no AC. Which is an Italian ‘Radiant’ brand. Im
located in Australia
03-25-2023 09:23 PM
Here is a picture form the Honeywell Manual:
Your hookup it probably Wiring a, above.
The AC Cooling Wizard
03-26-2023 01:03 AM
Hi thanks I agree. It a simple on or off. Does wiring work with the Nest?, if yes what are the two letters I would wire them to on the nest? Thanks
03-26-2023 10:03 AM
You will need a basic Nest thermostat, the one that uses AA batteries. The wire connections for your heating will be R and W.
The AC Cooling Wizard
03-26-2023 01:40 PM
great and thanks for your response and patience. Is this the best you are referring to. Google Nest Smart Programmable WiFi Thermostat - Snow White G4CVZ. I appreciate the help
03-28-2023 03:34 PM
Yes indeed. The thermostat you have does not require a third wire for the power common.
The AC Cooling Wizard
03-30-2023 08:28 PM
You didn't say what the thermostat is connected to, and there is a high probability that it is a 220-230Vac device that is incompatible with the none UK/Europe Nest thermostats.
Please verify the voltage at the A and B terminals.
04-06-2023 07:38 AM
Hello there,
I wanted to ensure that everything was covered here.
Thanks for all your help with compatibility checking, @CoolingWizard and @Patrick_Caezza.
@Popster, I hope you've got the answer you're looking for. If you're still in need of assistance, feel free to let us know.
Best,
Mark
04-09-2023 09:17 AM
Hi folks,
I wanted to follow up if you still need help. Please let me know if you’re still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.
I appreciate your help, Mark.
Thanks,
Jenelyn
04-10-2023 09:35 AM
Hi Popster,
We haven't heard from you in a while so we'll be locking this thread if there is no update within 24 hours. If you need assistance or want to discuss topics, feel free to start a new thread.
Regards,
Jenelyn