How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the easiest ways to optimize the daily 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 well or at all if you see an error code show up. The exact error code supplies useful information about the underlying problem, something a knowledgeable technician can use to offer solutions that much sooner.

Listed below are seven of the most frequent 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 can fix it and the projected cost to do so. Keep in mind that while the price will ultimately depend on the exact Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs along with any specific components necessary to wrap up repairs.

e298 - Critical

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

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

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll detach the power and gradually check each wire, ensuring they are fully attached into the connector with the correct amount of bare copper. After they locate the malfunctioning connector, it can be replaced for a new one.

e195 - Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will eventually power down. Presuming the breakers are on, you can check a few other places before consulting a professional technician.

Since this error can deplete your thermostat’s battery, the first step might be providing enough power to find out if this specific error code is what you’re facing. You can detach the thermostat from its base and provide power by using a USB cable. If it reveals error code 195, you may continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it's maybe best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This can stem from the breaker box, an error from the control board or through a bad connection in the thermostat. Your technician will meticulously inspect 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

While this error code isn’t critical, it can still stop you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining enough power. You can examine 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 might notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already 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 originating from an overcurrent. If too much power is transported inside the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as you can. You can then get in touch with a professional technician with the proper experience identifying and resolving electrical damage.

e73 - Critical

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