Installing a Nest thermostat is one of the most convenient ways to optimize the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work correctly or at all if you see an error code show up. The specific error code supplies useful information about the underlying problem, something a professional technician can use to provide solutions that much sooner.

Here are seven of the most likely error codes you may find on your Nest thermostat. We’ll explain the basics of each error code as well as how you can address it and the estimated cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can count on paying about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific hardware 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 detached from the system. 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 resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection might have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician should examine electrical connections and wiring until they uncover 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 begin inspecting connectors.

They’ll detach the power and progressively check each wire, making sure they are fully placed into the connector with the proper amount of bare copper. After they pinpoint the problem connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem lingers, 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 consulting a professional technician.

Because this error can deplete your thermostat’s battery, the first step may be providing enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power through a USB cable. If it presents 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 struggle to detect anything wrong with these components, it will probably be best to call a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. Your technician can carefully examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might 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 receiving adequate 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 may notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already 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 originating from an overcurrent. If excessive power is sent through the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you notice 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 straightaway. You can then get a hold of a professional technician with the necessary experience diagnosing and resolving electrical damage.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it may also be an issue with the wiring. After shutting 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 seems to be out of place, it’s best to contact a local professional.