Using a Nest thermostat is one of the best ways to optimize the daily schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make adjustments. But as you may expect, it won’t work correctly or at all if you see an error code appear. The precise error code provides useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much faster.

Here are seven of the most common error codes you may find on your Nest thermostat. We’ll review the basics of each error code on top of how you could address it and the estimated cost to do so. Don’t forget that while the investment will ultimately depend on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts needed to finish repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is shut off. Since this is a critical power error, the thermostat will swap to the backup battery system. The error message will continue to be displayed until the problem is resolved.

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

e294 – Critical

Critical error code e294 shows up 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 ensure it’s not merely a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.

They’ll detach the power and progressively check each wire, seeing to it that they are fully placed into the connector with the correct amount of uncovered copper. Once they find the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface 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. Assuming the breakers are on, you can check a handful of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step might be restoring enough power to figure out if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power with a USB cable. If it presents error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 may 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 through a bad connection in the thermostat. Your technician needs to carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Although this error code isn’t critical, it could still keep you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from getting sufficient power. You can check the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you can get a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required 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 that’s the result of an overcurrent. If too much power is being delivered using the Nest’s wiring, it can damage internal components and can 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 switch the power off straightaway. 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 signifies that the Rc wire is not getting power.

This may be as straightforward 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 inspect the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s a good idea to speak with a local professional.