How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the best ways to improve the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code show up. The specific error code offers useful information about the root of the problem, something a trained technician can use to present solutions that much quicker.

Listed below are seven of the most frequent error codes you could find on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you can solve it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the specific Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts required to complete repairs.

e298 - Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is detached from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will continue to be displayed until the issue is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician can check electrical connections and wiring until they locate 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 just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll detach the power and progressively check each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. When they pinpoint the damaged connector, it can be swapped for a new one.

e195 - Critical

This critical error code can surface when the weather outside is particularly 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 eventually shut down. In the event the breakers are on, you can check a few other places before consulting a professional technician.

As this error can deplete your thermostat’s battery, the first step might be providing enough power to determine if this specific error code is what you’re working with. You can detach the thermostat from its base and deliver power by using a USB cable. In the event it reveals error code 195, you may continue to visually check components like 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 contact a pro.

e103 - Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than needed. This will sometimes stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. A technician should cautiously examine 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 may still prevent you from using the Nest thermostat how you prefer to. Error code n260 pertains 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 inspect the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you can get a Nest Power Connector.

During installation of a Nest Power Connector, you may notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have 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 excessive power is being delivered inside the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off straightaway. You can then get a hold of a professional technician with the proper experience diagnosing and solving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This may be as straightforward as the breaker being shut off, but it could also be an issue with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check 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 contact a local professional.