Operating a Nest thermostat is one of the best ways to improve the everyday schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make improvements. But as you might expect, it won’t work well or at all if you see an error code show up. The specific error code offers useful information about the underlying problem, something a trained technician can use to present solutions that much faster.

Listed below are seven of the most frequent error codes you might discover on your Nest thermostat. We’ll review the basics of each error code along with how you could address it and the approximate cost to do so. Keep in mind that while the costs will ultimately be dependent on the exact Nest model, you can count on paying between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to wrap up 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 switch to the backup battery system. The error message will remain on display until the problem is fixed.

Losing power to your Nest thermostat can be for a number of 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 certified technician will check electrical connections and wiring until they locate 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 make sure it’s not simply a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.

They’ll disconnect the power and progressively check each wire, making sure they are fully attached into the connector with the correct amount of exposed copper. Once they find the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can show up when the weather outside is particularly hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually shut down. In the event the breakers are on, you can inspect a couple of other places before contacting a professional technician.

As this error can consume your thermostat’s battery, the first step might be supplying enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power by using a USB cable. If it reveals error code 195, you can continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 may 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 because of a bad connection in the thermostat. The technician will cautiously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it may still keep you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving enough power. You can examine the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead have 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 using the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s a good idea to turn the power off as soon as possible. You can then get a hold of a professional technician with the proper experience identifying and fixing electrical issues.

e73 – Critical

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

This may be as simple as the breaker being shut off, but it could also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s a good idea to contact a local professional.