Installing a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you can expect, it won’t work correctly 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.

Listed below are seven of the most frequent error codes you could find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you could solve it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs along with any specific components necessary to finish repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is detached from the system. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue is resolved.

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

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not simply a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll detach the power and slowly inspect each wire, making sure they are fully placed into the connector with the proper amount of exposed copper. Once they find the damaged connector, it can be swapped for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently turn off. Assuming the breakers are on, you can check a handful of other places before calling a professional technician.

Because this error can consume your thermostat’s battery, the first step could 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. Assuming 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 can’t uncover anything wrong with these components, it will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical malfunction 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 can stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. A technician needs to carefully investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving adequate power. You can check 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 may notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead need 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 that’s the result of an overcurrent. If excess power is transported using the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience detecting and resolving electrical damage.

e73 – Critical

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

This could be as simple as the breaker being switched off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s a good idea to contact a local professional.