Operating a Nest thermostat is one of the best ways to perfect the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make changes. But as you can expect, it won’t work well or at all if you see an error code show up. The specific error code provides useful information about the source of the problem, something a knowledgeable technician can use to provide solutions that much faster.
Listed below are seven of the most common error codes you may find on your Nest thermostat. We’ll explain the basics of each error code on top of how you can solve it and the estimated cost to do so. Don't forget that while the costs will ultimately hinge on the precise Nest model, you can anticipate paying between $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and appears when the power is disconnected from the system. Because this is a critical power error, the thermostat will switch 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 could have disconnected or become damaged, or a disconnection could have happened further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician can examine electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 shows up when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete 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 begin inspecting connectors.
They’ll shut off the power and gradually check each wire, seeing to it that they are fully attached into the connector with the proper amount of uncovered copper. After they pinpoint the damaged connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is especially hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will eventually shut down. In the event the breakers are on, you can search a handful of other places before consulting a professional technician.
Because this error can drain your thermostat’s battery, the first step might 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 supply power through a USB cable. In the event it displays error code 195, you may continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover 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 problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician needs to carefully inspect and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.
While this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving sufficient power. You can examine the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you can get a Nest Power Connector.
Due to installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Similar to error code e103, e104 is a critical error originating from an overcurrent. If excessive power is sent through the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s a good idea to turn the power off as soon as you can. You can then get in touch with a professional technician with the necessary experience diagnosing and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This could be as straightforward as the breaker being shut off, but it can also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s best to get in touch with a local professional.