02-05-2026 09:39 AM
I want my Nest thermostat Gen 4 to turn on the RTU fan on and off on a schedule. The Script Editor AI gave me a type of - type: device.command.ThermostatFanMode . However the validator says this is not a valid or recognized type.
What is the solution?
Answered! Go to the Recommended Answer.
02-08-2026 05:09 PM
Hi @Rodeng,
Thank you for posting in the community. I understand you are experiencing validation errors while using the Script Editor with AI to program the fan mode for your Google Nest Learning Thermostat (4th Gen) and Google Nest Learning Thermostat (3rd Gen). I am more than happy to help you.
Because your request involves advanced automation scripting, I recommend directing your questions to the Smart Home Developer Forum, for the most detailed resolution. They can provide expert guidance and specific code examples to resolve these validation errors.
If you have any questions regarding the script editor, you can visit this link on how to Create advanced home automations with the script editor for more information.
I hope this information helps!
Best regards,
Brian
02-05-2026 09:57 AM
The options given included type: device.command.SetFanSpeed however fan speed control is not available on the RTU. Anyway would setting it to 100.0% and 0.0% work? However it is not accepted by Validate on my guinea pig Gen 3 thermostat that I am using to write a script - is that a limitation of the Gen 3?
02-08-2026 05:09 PM
Hi @Rodeng,
Thank you for posting in the community. I understand you are experiencing validation errors while using the Script Editor with AI to program the fan mode for your Google Nest Learning Thermostat (4th Gen) and Google Nest Learning Thermostat (3rd Gen). I am more than happy to help you.
Because your request involves advanced automation scripting, I recommend directing your questions to the Smart Home Developer Forum, for the most detailed resolution. They can provide expert guidance and specific code examples to resolve these validation errors.
If you have any questions regarding the script editor, you can visit this link on how to Create advanced home automations with the script editor for more information.
I hope this information helps!
Best regards,
Brian
02-15-2026 12:58 PM
I have posted in that forum, however no one is replying. And I have exhausted the Script Editor links and helps. I need someone to create a script that will work with my system or tell me that the Google Nest cannot independently control furnace fan operation. In which case I will be returning the thermostats.
02-11-2026 04:02 PM
I'm struggling with Nest Gen4 Fan control script.
Gemini say the following below, however script editor Validate says this is an unknown type name device.command.FanControl
it is also not accepting FanMode and SetFanSpeed is not supported by this device
The Gen 4 model allows for granular control over your HVAC fan independently of heating/cooling.
device.command.FanControl: Manually toggles the fan.
Parameter: fanMode (on, off, circulate).
02-15-2026 01:13 PM
Script Editor Validate is not accepting device.command.FanControl as a valid type.