Using a Nest thermostat is one of the easiest 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 appear. The precise error code supplies useful information about the source of the problem, something a professional technician can use to provide solutions that much sooner.

Here are seven of the most common error codes you may find on your Nest thermostat. We’ll review the basics of each error code as well as how you might address it and the approximate cost to do so. Keep in mind that while the costs will ultimately depend on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should include travel and labor costs along with any specific hardware necessary 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 shut off. Because 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 problem is fixed.

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

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring should 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 just a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.

They’ll shut off the power and gradually look at each wire, ensuring they are fully placed into the connector with the proper amount of uncovered copper. When they pinpoint the malfunctioning connector, it can be swapped for a new one.

e195 – Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can break down and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can check a couple of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step may be supplying enough power to figure out if this specific error code is what you’re working with. You can detach the thermostat from its base and supply power by using a USB cable. In the event it displays error code 195, you can continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you can’t find anything wrong with these components, it will likely be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician needs to meticulously examine and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it may still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining adequate 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’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you might 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 have 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 stemming from an overcurrent. If too much 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 appear on your Nest thermostat and want to protect from electrical damage, it’s suggested to turn the power off as soon as possible. You can then contact a professional technician with the proper experience detecting and fixing electrical problems.

e73 – Critical

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

This will sometimes be as simple as the breaker being switched off, but it could also be an issue with the wiring. After switching 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 seems to be out of place, it’s a good idea to contact a local professional.