How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your HVAC system. This smart thermostat can learn 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 show up. The precise error code offers useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much sooner.

Listed below are seven of the most likely error codes you may discover on your Nest thermostat. We’ll review the basics of each error code as well as how you could address it and the estimated cost to do so. Keep in mind that while the price will ultimately hinge on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should include travel and labor costs on top of any specific parts 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 detached from the system. Since this is a critical power error, the thermostat will switch 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 several reasons. The wiring could have disconnected or become damaged, or a disconnection might have occurred further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician should inspect 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 needs to be reconfigured. More specifically, you’ll need the technician 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 start inspecting connectors.

They’ll disconnect the power and slowly check each wire, seeing to it that they are fully inserted into the connector with the correct 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 severely hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally power down. Presuming the breakers are on, you can inspect a few other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step could be providing 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 displays error code 195, you may continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will probably be best to call a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. The technician will carefully investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes 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 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 adequate 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 can get a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes 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 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 excessive power is sent using 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 straightaway. You can then get a hold of a professional technician with the necessary experience identifying and solving electrical malfunctions.

e73 - Critical

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