Operating a Nest thermostat is one of the easiest ways to optimize the day-to-day 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 well or at all if you see an error code appear. The specific error code offers useful information about the underlying problem, something a professional technician can use to provide 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 approximate cost to do so. Remember that while the costs will ultimately be dependent on the exact Nest model, you can count on paying around $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts required to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is shut off. As 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 numerous reasons. The wiring might have disconnected or become damaged, or a disconnection could have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician should examine electrical connections and wiring until they find the root of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform 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 start looking at connectors.

They’ll disconnect the power and slowly check each wire, seeing to it that they are fully attached into the connector with the correct amount of exposed copper. When they locate the malfunctioning 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 shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually shut down. Presuming the breakers are on, you can inspect a couple of other places before calling a professional technician.

As this error can consume 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 can continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it will probably be best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error 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 thanks to a faulty connection in the thermostat. The technician can carefully inspect 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

Even though this error code isn’t critical, it can still prevent you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining enough power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.

Due to 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

Like error code e103, e104 is a critical error originating from an overcurrent. If too much power is sent using the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s a good idea to switch the power off straightaway. You can then contact a professional technician with the appropriate experience identifying and resolving electrical malfunctions.

e73 – Critical

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

This may be as simple as the breaker being switched off, but it could also be an issue 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 best to speak with a local professional.