Received E195 error on Nest e thermostat.

[ches320]

My thermostat is show E195 error no power to R wire.  I reset and checked circuit breaker, reset Nest thermostat but nothing helped.  This is not a new install.  It has been working for years. All of a sudden, this error appeared.  I have not experienced any power outages when this error appeared.  What can I do to get this device to work normally? 

[Houptee]

You will need to go to the furnace and remove front panel. Hold the door switch in with your finger when panel is off. Now look at the control board see if any led lights are on. That will tell you if there is power to the board.  Then look for a fuse on the board that usually look like car push in fuses with a number on it for the amp rating. Possibly the fuse blew.

Or if you know how to use a multi meter you can set it to measure AC volts and test red R terminal to C common terminal at the nest and also test same at the furnace for 24-34 volts AC. If nothing then the transformer inside the furnace could have gone bad.

[Jenelyn_O]

Hi there,

Thanks for reaching out. I'm sorry for the delay. I just want to know if you were able to try the troubleshooting steps provided above. Also, you can visit this support article to get more information on how to troubleshoot E195 code you found on your Nest Thermostat. Please keep us posted. 

I appreciate your help, @Houptee.

Best,

Jenelyn

[Jenelyn_O]

Hi ches320,

Checking in — were you able to proceed with the troubleshooting? Please let us know how it goes.

Thanks,

Jenelyn

[Jenelyn_O]

Hello ches320,

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'll be locking this thread in 24 hours.

Regards,
Jenelyn