Installing a Nest thermostat is one of the best ways to improve the everyday schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you can expect, it won’t work properly or at all if you see an error code on the display. The exact error code offers useful information about the root of the problem, something a knowledgeable technician can use to provide solutions that much faster.
Here are seven of the most frequent error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you could address it and the projected cost to do so. Don't forget that while the price will ultimately depend on the exact Nest model, you can count on paying between $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts necessary to finish repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and appears when the power is shut off. As this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the issue is dealt with.
Losing power to your Nest thermostat can be for numerous reasons. The wiring might have disconnected or become damaged, or a disconnection may have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician will inspect electrical connections and wiring until they locate the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.
They’ll shut off the power and progressively inspect each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. When they find the problem connector, it can be swapped for a new one.
e195 - Critical
This critical error code can surface when the weather outside is especially hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently turn off. Assuming the breakers are on, you can check a handful of other places before consulting a professional technician.
As 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 working with. You can disconnect the thermostat from its base and deliver power through a USB cable. In the event it displays error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will likely be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than needed. This can stem from the breaker box, an error from the control board or through a bad connection in the thermostat. Your technician needs to meticulously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.
Although this error code isn’t critical, it could still keep you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining enough 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 can get a Nest Power Connector.
With installation of a Nest Power Connector, you might notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Like error code e103, e104 is a critical error that's the result of an overcurrent. If excessive power is sent using the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to guard against electrical damage, it’s recommended to switch the power off straightaway. You can then get in touch with a professional technician with the proper experience diagnosing and fixing electrical damage.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This may be as easy as the breaker being shut off, but it could also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s best to contact a local professional.