close up of a nest smart thermostat

Operating a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your comfort system. This smart thermostat can be taught your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code on the display. The exact error code offers useful information about the source of the problem, something a trained technician can use to offer solutions that much quicker.

Here are seven of the most common error codes you might find on your Nest thermostat. We’ll review the basics of each error code as well as how you might solve it and the estimated cost to do so. Don’t forget that while the costs will ultimately depend on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts required to finish repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears 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 issue is dealt with.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have appeared further along in your home’s electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable 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 problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll disconnect the power and slowly look at each wire, making sure they are fully placed into the connector with the proper amount of bare copper. Once 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 severely hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually power down. In the event the breakers are on, you can inspect a few other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step may be supplying enough power to determine if this specific error code is what you’re facing. You can disconnect the thermostat from its base and deliver power by using a USB cable. If it reveals error code 195, you should 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 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 suggests 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 what is safe and normal. This may stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician needs to 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

Even though this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate power. You can inspect the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you need a Nest Power Connector.

During 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 was already 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 sent through the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you see this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to turn the power off as soon as possible. You can then get in touch with a professional technician with the necessary experience diagnosing and solving 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 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 nothing is loose or damaged. If nothing seems to be out of place, it’s best to speak with a local professional.