Using a Nest thermostat is one of the most convenient ways to perfect the everyday 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 appear. The precise error code offers useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.

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 along with how you might address it and the projected cost to do so. Keep in mind that while the price will ultimately hinge on the specific Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific hardware needed to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the issue is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection may have happened further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician should check electrical connections and wiring until they find the root of the problem.

e294 – Critical

Critical error code e294 appears 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 ensure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and progressively look at each wire, making sure they are fully attached into the connector with the proper amount of bare copper. Once 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 especially hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently turn off. Assuming the breakers are on, you can check a handful of other places before calling a professional technician.

Since this error can consume your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power with a USB cable. Assuming it displays error code 195, you can continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t 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 issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician needs to carefully inspect 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

While this error code isn’t critical, it may still prevent you from using the Nest thermostat how you prefer to. Error code n260 pertains 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 adjust the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you will sometimes notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required 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 that’s the result of an overcurrent. If too much power is sent using the Nest’s wiring, it may damage internal components and may 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 a good idea to shut the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience diagnosing and solving electrical problems.

e73 – Critical

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

This may be as easy as the breaker being switched off, but it may also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing looks to be out of place, it’s a good idea to contact a local professional.