Operating a Nest thermostat is one of the easiest ways to optimize the everyday schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you can expect, it won’t work correctly or at all if you see an error code on the display. The exact error code provides useful information about the source of the problem, something a professional technician can use to present solutions that much quicker.

Listed below are seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could fix it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the specific Nest model, you can expect to pay around $75-$200 for repairs. This should include travel and labor costs as well as any specific components required to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is disconnected from the system. Because 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 could have happened further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can examine electrical connections and wiring until they find the root of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs 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 make sure it’s not merely a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.

They’ll shut off the power and gradually check each wire, seeing to it that they are fully placed into the connector with the correct amount of bare copper. After they find the problem connector, it can be swapped for a new one.

e195 – Critical

This critical error code can show up when the weather outside is especially hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally shut down. In the event the breakers are on, you can search a few other places before calling a professional technician.

As this error can consume your thermostat’s battery, the first step may be restoring enough power to figure out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and deliver power with a USB cable. If it presents error code 195, you may continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This will sometimes stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. A technician will carefully inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it can still keep you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of 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 modify the wiring itself if there is. If not, you can get 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 is 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 stemming from an overcurrent. If excessive power is being delivered through the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you notice this error code pop up 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 possible. You can then get a hold of a professional technician with the proper experience diagnosing and solving electrical damage.

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 turned off, but it could also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.