Installing a Nest thermostat is one of the best ways to optimize the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code appear. The specific error code provides useful information about the source of the problem, something a professional technician can use to offer solutions that much quicker.

Let’s consider seven of the most likely error codes you could find on your Nest thermostat. We’ll review the basics of each error code along with how you can fix it and the approximate cost to do so. Keep in mind that while the costs will ultimately hinge on the specific Nest model, you can expect to pay around $75-$200 for repairs. This should include travel and labor costs as well as any specific components needed to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is disconnected from the system. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is fixed.

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 may be the circuit breaker, fuse box or system switch. A certified technician will inspect electrical connections and wiring until they uncover the root of the problem.

e294 – Critical

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

They’ll disconnect the power and gradually look at each wire, seeing to it that they are fully placed into the connector with the proper amount of uncovered copper. When they pinpoint the problem 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 fail and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently power down. In the event the breakers are on, you can examine a handful of other places before consulting a professional technician.

As this error can drain 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 separate the thermostat from its base and supply power with a USB cable. Assuming it reveals 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 can’t uncover anything wrong with these components, it’s maybe best to call a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This can stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. A technician will cautiously inspect 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 could still keep you from using the Nest thermostat like normal. 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 enough power. You can examine the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. 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 stemming from an overcurrent. If excess power is sent using the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get a hold of a professional technician with the proper experience detecting and fixing electrical malfunctions.

e73 – Critical

When your thermostat displays error code e73, it indicates 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 turning 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 a good idea to speak with a local professional.