Operating a Nest thermostat is one of the easiest ways to optimize the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work well or at all if you see an error code show up. The exact error code offers useful information about the underlying problem, something a professional technician can use to provide solutions that much quicker.

Listed below are seven of the most common error codes you may find on your Nest thermostat. We’ll review the basics of each error code on top of how you can address it and the approximate cost to do so. Keep in mind that while the price will ultimately be dependent on the exact Nest model, you can anticipate paying between $75-$200 for repairs. This should include travel and labor costs as well as any specific components needed to wrap up repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is disconnected from the system. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the issue is dealt with.

Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A trained 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 has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and slowly look at each wire, ensuring they are fully attached into the connector with the proper amount of exposed copper. Once they locate the malfunctioning connector, it can be exchanged 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 lingers, the backup battery in your thermostat drains and the thermostat will finally power down. Presuming the breakers are on, you can check a couple 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 dealing with. You can separate the thermostat from its base and provide power by using a USB cable. Assuming it presents error code 195, you can continue to visually inspect components like 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 get in touch with a pro.

e103 – Critical

Another critical error code, e103 indicates 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 necessary. This can stem from the breaker box, an error from the control board or because of a bad 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 can still stop you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving enough 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 can get a Nest Power Connector.

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

Just like error code e103, e104 is a critical error originating from an overcurrent. If too much power is being delivered through the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s recommended to switch the power off as soon as possible. You can then contact a professional technician with the proper experience identifying and resolving electrical malfunctions.

e73 – Critical

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

This could be as straightforward as the breaker being shut off, but it can also be an issue with the wiring. After shutting 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 time to contact a local professional.