Using a Nest thermostat is one of the easiest ways to optimize the day-to-day schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you can expect, it won’t work well or at all if you see an error code appear. The exact error code offers useful information about the root of the problem, something a trained technician can use to provide solutions that much faster.

Listed below are seven of the most likely error codes you might find on your Nest thermostat. We’ll explain the basics of each error code as well as how you could address it and the projected cost to do so. Remember that while the price will ultimately depend on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should include things like travel and labor costs along with any specific components necessary to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is detached from the system. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen until the problem is fixed.

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

e294 – Critical

Critical error code e294 appears 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 complete a factory reset of your thermostat to ensure it’s not merely a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and gradually inspect each wire, making sure they are fully attached into the connector with the proper amount of uncovered copper. Once they find the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally power down. Presuming the breakers are on, you can check a few other places before calling a professional technician.

Since 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 separate the thermostat from its base and deliver power with a USB cable. In the event it reveals error code 195, you may continue to visually check components like the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will likely be best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This may stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. Your technician needs to carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

While this error code isn’t critical, it might still keep you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 appear. This can be resolved 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 stemming from an overcurrent. If excess power is transported inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to turn the power off as soon as you can. You can then get a hold of a professional technician with the appropriate experience diagnosing and resolving electrical malfunctions.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it could also be an issue with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s time to get in touch with a local professional.