Installing a Nest thermostat is one of the best ways to perfect the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make changes. But as you may expect, it won’t work correctly or at all if you see an error code show up. The specific error code offers useful information about the underlying problem, something a professional technician can use to present solutions that much faster.

Let’s consider seven of the most common error codes you may discover on your Nest thermostat. We’ll review the basics of each error code along with how you could fix it and the projected cost to do so. Don’t forget that while the costs will ultimately hinge on the precise Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs on top of any specific parts necessary to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is disconnected from the system. As this is a critical power error, the thermostat will change 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 numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician will examine electrical connections and wiring until they uncover the source of the problem.

e294 – Critical

Critical error code e294 shows up 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 issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and gradually check each wire, ensuring 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 surface 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 eventually power down. Assuming the breakers are on, you can search a couple of other places before calling a professional technician.

As this error can drain your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re dealing with. You can detach the thermostat from its base and supply power with a USB cable. If it reveals error code 195, you may continue to visually examine components like 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 get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. A technician needs to meticulously examine and test the Nest’s electrical system to determine 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 how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving adequate power. You can inspect 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.

During installation of a Nest Power Connector, you might notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead have 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 stemming from an overcurrent. If excess power is being delivered through the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to switch the power off as soon as possible. You can then contact a professional technician with the appropriate experience diagnosing and resolving electrical damage.

e73 – Critical

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

This will sometimes be as easy as the breaker being shut off, but it can also be something with the wiring. After shutting 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 looks to be out of place, it’s a good idea to get in touch with a local professional.