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 daily schedule of your heating and cooling. This smart thermostat can recognize 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 on the display. The precise error code supplies useful information about the source of the problem, something a trained technician can use to present solutions that much sooner.

Let's consider seven of the most likely error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might solve it and the projected cost to do so. Remember that while the price will ultimately depend on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts required to wrap up repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is disconnected from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue is fixed.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection may have happened further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician should inspect 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 needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not merely a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and gradually check each wire, ensuring they are fully attached into the connector with the proper amount of exposed copper. When they locate the malfunctioning connector, it can be swapped for a new one.

e195 - Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can search a handful of other places before calling a professional technician.

As this error can drain your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power by using a USB cable. If it displays error code 195, you may continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it will likely be best to call a pro.

e103 - Critical

Another critical error code, e103 suggests an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This may stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. A technician should cautiously 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

Although this error code isn’t critical, it might still prevent 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 missing one can block your Nest from getting sufficient 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’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was 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 originating from an overcurrent. If excessive power is being delivered through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to switch the power off as soon as you can. You can then contact a professional technician with the proper experience detecting and solving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This will sometimes be as simple as the breaker being switched off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s best to speak with a local professional.