topic Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running) in Nest Thermostats

Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running).

rgaila — Tue, 31 Aug 2021 16:32:41 GMT

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Original Poster: Jimmy919

Contractor installed a new Mitsubishi ducted split system (SEZ-KD09NA4) and a PAC-us444CN-1 thermostat adapter. After installing the Nest 2020 thermostat the unit ran in AC mode for several hours and then shut off. Contractor reset and it still shut off. This happened on two occasions. HVAC contractor (google guaranteed) installed a Honeywell thermostat and everything works fine. I was told by the contractor that the Mitsubishi unit and adapter is only compatible with previous generation Nest thermostats and not the newest 2020 version. I did not get the opportunity to look for error codes. Anyone encounter a similar situation? I called Mitsubishi USA tech support and was told that they do not have info or verify compatibility.

Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running)

rgaila — Tue, 31 Aug 2021 16:33:05 GMT

Hi Jim,

Sorry to hear about your compatibility issues! That is frustrating to have to coordinate in your home. I'm happy to look into this for you.

We do have the Compatibility Checker, a widget to see if your system is compatible. Often times, users send in photos of their wiring setups to us to see our best recommendation. Unfortunately, it's not always possible to assuredly say "yes/no" since we wouldn't know the specifics of particular HVAC systems, nor is it easy to verify compatibility/incompatibility with them. I'm sorry that this meant a long process of trial and error for you and hope your home can be set the way you want it to be.

Let me know if you have any further questions for us.

-From Ai, Community Specialist.

Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running)

dropair — Tue, 11 Apr 2023 10:08:39 GMT

You can try the dropair adapter for Mitsubishi. Check the YouTube channel: https://youtu.be/KKlfcuqT3HQ

Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running)

zoeuvre — Tue, 25 Apr 2023 19:14:40 GMT

Hi there,

Thanks for stopping by @dropair. In the meantime, I'll go ahead and lock this thread within 24 hours. If you run into any more questions in the future, please feel free to create a new thread.

Regards,

Zoe

Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running)

dropair — Wed, 26 Apr 2023 01:53:48 GMT

No problem. thank you.

Re: Mitsubishi PAC-US444CN-1 not compatible with 2020 Nest thermostat (unit shuts off after running)

zoeuvre — Wed, 26 Apr 2023 17:04:28 GMT

Hey dropair,

Alright. I'll be locking this thread if there is no update within 24 hours. If you have any other questions in the future, please start a new thread.

Cheers,

Zoe