How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the easiest ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work correctly or at all if you see an error code on the display. The precise error code supplies useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much quicker.

Here are seven of the most frequent error codes you might find on your Nest thermostat. We’ll review the basics of each error code along with how you might solve it and the projected cost to do so. Remember that while the costs will ultimately depend on the precise Nest model, you can count on paying about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific components required to wrap up repairs.

e298 - Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is disconnected from the system. Because 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 problem is dealt with.

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 the electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician can check 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 should 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 merely a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.

They’ll shut off the power and gradually look at each wire, seeing to it that they are fully placed into the connector with the correct amount of bare copper. Once they locate 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 lasts, the backup battery in your thermostat depletes and the thermostat will subsequently power down. Assuming the breakers are on, you can check a couple of other places before consulting a professional technician.

Because this error can drain your thermostat’s battery, the first step might be restoring enough power to determine if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power through a USB cable. Assuming it presents 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 can't uncover anything wrong with these components, it's maybe best to contact a pro.

e103 - Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than necessary. This can stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician needs to cautiously investigate and test the Nest’s electrical system to understand 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 may 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 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 need a Nest Power Connector.

Due to installation of a Nest Power Connector, you will sometimes notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead need to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 - Critical

Like error code e103, e104 is a critical error that's the result of an overcurrent. If too much power is sent using the Nest’s wiring, it can damage internal components and can 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 suggested to shut the power off as soon as you can. You can then get in touch with a professional technician with the proper experience diagnosing and solving electrical issues.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This might be as easy as the breaker being shut off, but it can also be an issue with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure nothing is loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.