Operating a Nest thermostat is one of the best ways to improve 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 well or at all if you see an error code appear. The exact error code supplies useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.

Here are seven of the most likely error codes you might discover on your Nest thermostat. We’ll review the basics of each error code on top of how you could fix it and the estimated cost to do so. Remember that while the price will ultimately hinge on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs along with any specific components required to finish 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. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen until the problem is resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection may have occurred further along in your electrical system. This may 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 appears when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.

They’ll detach the power and progressively look at each wire, seeing to it that they are fully placed into the connector with the correct amount of bare copper. Once they pinpoint 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 lasts, the backup battery in your thermostat drains and the thermostat will eventually power down. Presuming the breakers are on, you can inspect a few other places before calling a professional technician.

Because this error can deplete your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power by using a USB cable. If it reveals error code 195, you should 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 detect anything wrong with these components, it will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This will sometimes stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. The technician should cautiously 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

While this error code isn’t critical, it could still prevent you from using the Nest thermostat how you prefer 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 obtaining 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 need a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be resolved 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

Similar to error code e103, e104 is a critical error originating from an overcurrent. If excessive power is being delivered inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to shut the power off as soon as possible. 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 means that the Rc wire is not receiving power.

This will sometimes be as straightforward as the breaker being turned off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s a good idea to get in touch with a local professional.