Operating a Nest thermostat is one of the easiest ways to improve the daily schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make improvements. But as you can 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 underlying problem, something a knowledgeable technician can use to offer solutions that much faster.

Here are seven of the most common error codes you might discover on your Nest thermostat. We’ll review the basics of each error code on top of how you can address it and the estimated cost to do so. Remember that while the costs will ultimately hinge on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs along with any specific hardware necessary 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 swap to the backup battery system. The error message will remain on display until the problem is resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have happened further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should examine electrical connections and wiring until they locate 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, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not merely a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and slowly check each wire, ensuring they are fully attached into the connector with the proper amount of uncovered copper. Once they find the damaged 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 sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally power down. Presuming the breakers are on, you can inspect a few other places before contacting a professional technician.

Since this error can consume your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power by using a USB cable. In the event it reveals error code 195, you may continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. A technician will meticulously examine and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Although this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from getting adequate 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.

With 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 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 being delivered inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as you can. You can then get a hold of a professional technician with the appropriate experience diagnosing and solving electrical malfunctions.

e73 – Critical

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

This could be as easy as the breaker being turned off, but it could also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s a good idea to get in touch with a local professional.