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 perfect the day-to-day schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you can 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 knowledgeable technician can use to present solutions that much sooner.

Let's consider seven of the most frequent error codes you may find on your Nest thermostat. We’ll review the basics of each error code on top of how you can fix it and the approximate cost to do so. Remember that while the costs will ultimately be dependent on the specific Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts required to complete repairs.

e298 - Critical

This critical error code is limited to new 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 swap to the backup battery system. The error message will continue to be displayed until the issue is resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician should inspect 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 make sure it’s not merely 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 gradually look at each wire, making sure they are fully placed into the connector with the proper amount of bare copper. When they pinpoint the malfunctioning connector, it can be replaced for a new one.

e195 - Critical

This critical error code can surface when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally power down. Assuming the breakers are on, you can check a couple of other places before calling a professional technician.

Because this error can deplete your thermostat’s battery, the first step could be providing enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power through a USB cable. If it reveals error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you can't find anything wrong with these components, it will likely be best to get in touch with 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 experiencing more power than necessary. This can stem from the breaker box, an error from the control board or through a bad connection in the thermostat. A technician will carefully examine and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it could still prevent you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from getting enough 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’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead have 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 stemming from an overcurrent. If too much power is sent through the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s a good idea to switch the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience diagnosing and fixing electrical malfunctions.

e73 - Critical

When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This may be as straightforward as the breaker being shut 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 inspect 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.