Installing a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make adjustments. But as you may expect, it won’t work correctly or at all if you see an error code on the display. The specific error code provides useful information about the source of the problem, something a professional technician can use to offer solutions that much faster.

Here are seven of the most frequent 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 fix it and the approximate cost to do so. Keep in mind that while the investment will ultimately be dependent on the specific Nest model, you can count on paying between $75-$200 for repairs. This should also cover travel and labor costs on top of any specific parts necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to newer 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 swap to the backup battery system. The error message will remain on the screen until the problem is resolved.

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

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs 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 just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and progressively look at each wire, making sure they are fully placed into the connector with the correct amount of exposed copper. When they locate the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will eventually shut down. Assuming the breakers are on, you can inspect a handful of other places before consulting a professional technician.

As this error can deplete your thermostat’s battery, the first step may be providing 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 provide power by using a USB cable. In the event it presents error code 195, you should continue to visually check components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’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 indicates an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than necessary. This may stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician should cautiously examine and test the Nest’s electrical system to determine 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 keep you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of 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.

With installation of a Nest Power Connector, you might notice error code E297 show up. This can be remedied 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

Like error code e103, e104 is a critical error that’s the result of an overcurrent. If excess power is sent inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to guard against electrical damage, it’s suggested to shut the power off as soon as you can. You can then contact a professional technician with the proper experience identifying and resolving electrical issues.

e73 – Critical

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

This might be as simple as the breaker being turned off, but it could also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s best to speak with a local professional.