Installing a Nest thermostat is one of the best 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 might expect, it won’t work properly or at all if you see an error code show up. The exact error code provides useful information about the underlying problem, something a trained technician can use to offer solutions that much faster.

Here are seven of the most common error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code on top of how you might solve it and the approximate cost to do so. Keep in mind that while the costs will ultimately be dependent on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts required to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is detached from the system. Since 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 dealt with.

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

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not simply a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.

They’ll detach the power and slowly check each wire, seeing to it that they are fully attached into the connector with the proper amount of exposed copper. When 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 especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually shut down. In the event the breakers are on, you can check a couple of other places before contacting a professional technician.

As this error can drain your thermostat’s battery, the first step may be providing 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 like the wiring as well as your air conditioner’s air filter or drainage system. If you can’t detect anything wrong with these components, it’s maybe best to call a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing 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 defective connection in the thermostat. Your technician should carefully investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it may still prevent you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining sufficient 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’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with 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

Similar to 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 can damage internal components and may even be a fire hazard. If you see this error code show up on your Nest thermostat and want to guard against electrical damage, it’s suggested to shut the power off as soon as possible. You can then get in touch with a professional technician with the proper experience diagnosing and resolving electrical issues.

e73 – Critical

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

This might be as easy 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 appears to be out of place, it’s a good idea to get in touch with a local professional.