Operating a Nest thermostat is one of the best ways to optimize the everyday schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you may 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 root of the problem, something a professional technician can use to offer solutions that much faster.

Here are seven of the most common error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you can fix it and the approximate cost to do so. Don’t forget that while the investment will ultimately be dependent on the precise Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific hardware required to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and appears when the power is disconnected from the system. Because 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 numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician will examine electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 appears 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 perform a factory reset of your thermostat to ensure it’s not simply a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and gradually look at each wire, making sure they are fully attached into the connector with the correct amount of exposed copper. Once they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually power down. Assuming the breakers are on, you can search a couple of other places before consulting a professional technician.

Because this error can deplete your thermostat’s battery, the first step might be supplying enough power to find out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power by using a USB cable. If it reveals 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 don’t detect anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. A technician can meticulously inspect and test the Nest’s electrical system to understand 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 could still stop you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving adequate 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’ll need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with 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 stemming from an overcurrent. If excess power is transported inside the Nest’s wiring, it could 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 protect from electrical damage, it’s suggested to switch the power off as soon as you can. You can then contact a professional technician with the necessary experience detecting and fixing electrical malfunctions.

e73 – Critical

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

This could be as easy as the breaker being shut off, but it could also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.