Operating a Nest thermostat is one of the best ways to improve the everyday schedule of your HVAC 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 on the display. The exact error code offers useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.

Let’s consider seven of the most common error codes you might find on your Nest thermostat. We’ll review the basics of each error code as well as how you might fix it and the approximate cost to do so. Don’t forget that while the investment will ultimately depend on the precise Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific parts necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is detached from the system. As 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 issue is resolved.

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

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not simply a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll disconnect the power and slowly check each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. After they locate the problem connector, it can be swapped 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 sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally turn off. In the event the breakers are on, you can check a handful of other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power with a USB cable. If it presents error code 195, you should continue to visually examine components including 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 error 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 may stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. Your technician will carefully 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

Although this error code isn’t critical, it could still prevent 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 sufficient 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 can get a Nest Power Connector.

With 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 has already been installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Similar to error code e103, e104 is a critical error that’s the result of an overcurrent. If too much power is being delivered through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to guard against electrical damage, it’s suggested to turn the power off straightaway. You can then get in touch with a professional technician with the proper experience identifying and fixing electrical problems.

e73 – Critical

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

This could be as simple as the breaker being turned off, but it could also be something with the wiring. After switching 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.