Using a Nest thermostat is one of the best ways to optimize the daily schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you might expect, it won’t work correctly or at all if you see an error code appear. The specific error code offers useful information about the underlying problem, something a trained technician can use to provide solutions that much sooner.

Let’s consider seven of the most likely error codes you could encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you could solve it and the projected cost to do so. Keep in mind that while the costs will ultimately depend on the precise Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts required to finish repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen until the issue is dealt with.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection could have occurred further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician can inspect electrical connections and wiring until they uncover the root of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring has 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 make sure it’s not merely a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start checking connectors.

They’ll detach the power and slowly inspect each wire, ensuring they are fully placed into the connector with the proper amount of bare copper. Once they locate 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 delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally power down. Presuming the breakers are on, you can examine a couple of other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step may be supplying enough power to find out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and supply power by using a USB cable. If it presents error code 195, you should continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t 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 indicates an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician should 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.

n260

While this error code isn’t critical, it could still prevent you from using the Nest thermostat how you prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from obtaining sufficient power. You can examine 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.

With installation of a Nest Power Connector, you may notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already 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 excessive power is being delivered through the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see 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 contact a professional technician with the necessary experience diagnosing and fixing electrical malfunctions.

e73 – Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power.

This may be as straightforward as the breaker being turned off, but it may also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s a good idea to speak with a local professional.