Using a Nest thermostat is one of the best ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make adjustments. But as you may expect, it won’t work properly or at all if you see an error code appear. The exact error code offers useful information about the underlying problem, something a professional technician can use to offer solutions that much faster.
Listed below are seven of the most common error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might fix it and the approximate cost to do so. Don't forget that while the price will ultimately depend on the specific Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware needed to finish repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and appears when the power is detached from the system. Since 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 fixed.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician can examine electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.
They’ll detach the power and slowly look at each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. When they find the malfunctioning connector, it can be swapped for a new one.
e195 - Critical
This critical error code can show up 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 subsequently shut down. In the event the breakers are on, you can search a couple of other places before consulting a professional technician.
Since this error can consume your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power by using a USB cable. Assuming it presents 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 suggests an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. The technician will cautiously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it can still keep 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 adequate power. You can examine the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.
Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead need 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 stemming from an overcurrent. If excess power is transported inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to switch the power off straightaway. You can then get in touch with a professional technician with the necessary experience detecting and fixing electrical issues.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This will sometimes be as straightforward as the breaker being switched off, but it can also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.