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 HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. 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 supplies useful information about the source of the problem, something a trained technician can use to present solutions that much sooner.

Here are seven of the most likely error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you might fix it and the estimated cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific components needed to complete repairs.

e298 - Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. Since this is a critical power error, the thermostat will switch 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 several reasons. The wiring could have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician should examine electrical connections and wiring until they uncover the source 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 complete a factory reset of your thermostat to ensure it’s not simply a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. When they locate the problem connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will subsequently power down. Presuming the breakers are on, you can search a few other places before consulting a professional technician.

As this error can drain your thermostat’s battery, the first step could be supplying enough power to determine if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power with a USB cable. If it displays error code 195, you should continue to visually check components such as 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's maybe best to contact a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than needed. This can stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. Your technician can carefully 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

Even though this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from getting 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’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you might notice error code E297 be displayed. 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 excess power is being delivered using the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to turn the power off straightaway. You can then contact a professional technician with the appropriate experience detecting and fixing electrical damage.

e73 - Critical

When your thermostat displays error code e73, it means that the Rc wire is not getting power. This might be as simple as the breaker being shut off, but it may also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s time to speak with a local professional.