Using 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 improvements. But as you might expect, it won’t work correctly or at all if you see an error code on the display. The precise error code provides useful information about the source of the problem, something a trained technician can use to present solutions that much faster.

Listed below are seven of the most common error codes you could find on your Nest thermostat. We’ll explain the basics of each error code on top of how you might address it and the approximate cost to do so. Keep in mind that while the investment will ultimately hinge on the precise Nest model, you can expect to pay about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware necessary to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is disconnected from the system. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the problem is resolved.

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

e294 – Critical

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

They’ll detach the power and gradually check each wire, seeing to it that they are fully inserted into the connector with the correct amount of uncovered copper. After they locate the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can show up when the weather outside is particularly hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will eventually shut down. Presuming the breakers are on, you can examine a few other places before calling a professional technician.

As this error can deplete your thermostat’s battery, the first step could 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 deliver power through a USB cable. In the event it displays 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 struggle to detect 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 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 faulty connection in the thermostat. A technician will carefully examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

While this error code isn’t critical, it might 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 not having one can block your Nest from obtaining enough 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 can get a Nest Power Connector.

With installation of a Nest Power Connector, you might 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

Similar to error code e103, e104 is a critical error originating from an overcurrent. If too much power is sent through the Nest’s wiring, it can 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 take steps to prevent electrical damage, it’s suggested to turn the power off as soon as possible. You can then get in touch with a professional technician with the proper experience detecting and fixing electrical malfunctions.

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 inspect 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 get in touch with a local professional.