Using a Nest thermostat is one of the easiest ways to improve the day-to-day schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work correctly or at all if you see an error code on the display. The exact error code supplies useful information about the root of the problem, something a trained technician can use to offer solutions that much faster.
Listed below are seven of the most likely error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you can fix it and the approximate cost to do so. Don't forget that while the costs will ultimately be dependent on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should include travel and labor costs along with any specific components needed to complete repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and appears when the power is detached from the system. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the problem is resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection might have occurred further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician can examine electrical connections and wiring until they uncover the root of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not merely a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.
They’ll shut off the power and gradually inspect each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. When they find the problem connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can appear when the weather outside is particularly hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally turn off. Assuming the breakers are on, you can check a few other places before contacting a professional technician.
Because this error can consume your thermostat’s battery, the first step could be providing enough power to figure out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and supply power by using a USB cable. If it displays error code 195, you should continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you can't uncover anything wrong with these components, it will probably be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. Your technician can carefully inspect and test the Nest’s electrical system to figure out where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
Even though this error code isn’t critical, it may still prevent you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from getting enough power. You can inspect the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you can get a Nest Power Connector.
Due to installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Just like error code e103, e104 is a critical error originating from an overcurrent. If excess power is transported using the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s suggested to switch the power off straightaway. You can then get in touch with a professional technician with the proper experience detecting and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This might be as easy as the breaker being switched off, but it can also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s best to speak with a local professional.