Installing a Nest thermostat is one of the easiest ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code on the display. The precise error code offers useful information about the underlying problem, something a trained technician can use to provide solutions that much sooner.

Here are seven of the most likely error codes you may find on your Nest thermostat. We’ll explain the basics of each error code along with how you might solve it and the projected cost to do so. Remember that while the costs will ultimately hinge on the exact 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 needed to finish repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is shut off. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the problem is resolved.

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 the electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician should check 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 needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and slowly look at each wire, making sure they are fully placed into the connector with the correct amount of uncovered copper. After they pinpoint the malfunctioning connector, it can be replaced for a new one.

e195 – Critical

This critical error code can surface when the weather outside is severely 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 eventually power down. Presuming the breakers are on, you can check a handful of other places before consulting a professional technician.

As this error can drain your thermostat’s battery, the first step could be supplying enough power to find out if this specific error code is what you’re facing. You can detach the thermostat from its base and provide power by using a USB cable. In the event it presents error code 195, you should continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can’t detect anything wrong with these components, it will probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting 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 bad connection in the thermostat. A technician needs to carefully examine and test the Nest’s electrical system to determine 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 keep 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 missing one can block your Nest from receiving sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you need a Nest Power Connector.

Due to installation of a Nest Power Connector, you will sometimes 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

Like error code e103, e104 is a critical error originating from an overcurrent. If excessive power is transported using the Nest’s wiring, it may damage internal components and can 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 shut the power off straightaway. You can then get in touch with a professional technician with the appropriate experience identifying and fixing electrical problems.

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 could also be something with the wiring. After shutting 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 best to get in touch with a local professional.