Operating a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you might expect, it won’t work well or at all if you see an error code appear. The specific error code provides useful information about the root of the problem, something a trained technician can use to present solutions that much quicker.

Let’s consider seven of the most likely error codes you might encounter 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. Remember that while the investment will ultimately be dependent on the exact Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs along with any specific components needed 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. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the issue is fixed.

Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in your home’s electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician will inspect electrical connections and wiring until they uncover the source of the problem.

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring has 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 ensure it’s not simply a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.

They’ll detach the power and progressively check each wire, ensuring they are fully placed into the connector with the proper amount of exposed copper. When they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is particularly hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally power down. Presuming the breakers are on, you can check a couple of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step may be restoring enough power to determine if this specific error code is what you’re facing. You can disconnect the thermostat from its base and supply power through a USB cable. Assuming it presents error code 195, you can continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than needed. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. A technician needs to cautiously investigate 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

While this error code isn’t critical, it could still keep you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving enough power. You can check the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is 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 excess power is transported using the Nest’s wiring, it can damage internal components and can 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 recommended to turn the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience identifying and solving electrical damage.

e73 – Critical

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

This might be as easy as the breaker being shut 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 none of them are loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.