Installing a Nest thermostat is one of the best ways to improve the daily schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make changes. But as you might expect, it won’t work correctly or at all if you see an error code appear. The exact error code offers useful information about the root of the problem, something a professional technician can use to offer solutions that much faster.

Let’s consider seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you might solve it and the estimated cost to do so. Don’t forget that while the costs will ultimately depend on the exact 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 required to wrap up 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. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on the screen until the problem is dealt with.

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

e294 – Critical

Critical error code e294 is displayed 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 make sure it’s not simply a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start looking at connectors.

They’ll shut off the power and progressively check each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. Once they locate the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally shut down. Assuming the breakers are on, you can check a handful of other places before contacting a professional technician.

Because this error can consume your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and supply power with a USB cable. In the event it reveals error code 195, you can continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. A technician will meticulously investigate 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

While this error code isn’t critical, it can still keep 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 receiving enough power. You can examine the Nest’s C connector for the presence of a C wire and adjust 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 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 excess power is transported using the Nest’s wiring, it may damage internal components and can 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 recommended to switch the power off straightaway. You can then get in touch with a professional technician with the proper experience detecting and fixing electrical damage.

e73 – Critical

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

This might be as easy as the breaker being turned off, but it may also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s best to get in touch with a local professional.