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 day-to-day schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make adjustments. But as you might expect, it won’t work properly or at all if you see an error code show up. The precise error code supplies useful information about the underlying problem, something a professional technician can use to provide solutions that much faster.

Listed below are seven of the most frequent error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code along with how you can address it and the approximate cost to do so. Remember that while the costs will ultimately depend on the specific Nest model, you can anticipate paying between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to complete repairs.

e298 - Critical

This critical error code is limited to the latest 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 change to the backup battery system. The error message will remain on the screen until the problem is fixed.

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

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.

They’ll disconnect the power and gradually look at each wire, making sure they are fully attached into the connector with the proper amount of bare copper. After they locate the damaged connector, it can be swapped for a new one.

e195 - Critical

This critical error code can show up when the weather outside is especially hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently power down. In the event the breakers are on, you can inspect a handful of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step might be restoring enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and provide power through a USB cable. If it presents error code 195, you may continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you can't detect anything wrong with these components, it will likely be best to contact a pro.

e103 - Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. A technician can carefully inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it can still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving enough power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead need 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 originating from an overcurrent. If excessive power is transported inside the Nest’s wiring, it may 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 protect from electrical damage, it’s a good idea to shut the power off as soon as you can. You can then get a hold of a professional technician with the appropriate experience diagnosing and solving electrical damage.

e73 - Critical

When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This may be as simple as the breaker being switched off, but it could also be something with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s best to get in touch with a local professional.