Operating a Nest thermostat is one of the easiest ways to perfect the day-to-day schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make improvements. But as you might expect, it won’t work properly or at all if you see an error code appear. The specific error code offers useful information about the source of the problem, something a trained technician can use to present solutions that much faster.

Listed below are seven of the most frequent error codes you may find on your Nest thermostat. We’ll explain the basics of each error code along with how you might fix it and the estimated cost to do so. Keep in mind that while the costs will ultimately be dependent on the precise Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware necessary to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is disconnected from the system. 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 issue is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection may have happened further along in your home’s electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician will 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 should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not simply a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and slowly check each wire, seeing to it that they are fully placed into the connector with the proper amount of uncovered copper. After they locate the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is especially hot. The HVAC system can fail and stop sending 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 check a handful of other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step might be supplying enough power to figure out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and supply power with a USB cable. If it reveals error code 195, you can continue to visually examine components like 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 probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician can cautiously investigate 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

Even though this error code isn’t critical, it might still stop you from using the Nest thermostat like normal. 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 adjust the wiring itself if there is. If not, you can get 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 need 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 that’s the result of an overcurrent. If excessive power is sent inside the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s a good idea to turn the power off as soon as possible. You can then get a hold of a professional technician with the necessary experience diagnosing and solving electrical damage.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it may also be a problem with the wiring. After turning 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 speak with a local professional.