How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Installing a Nest thermostat is one of the best ways to improve the everyday schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make improvements. But as you may 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 source of the problem, something a trained technician can use to present solutions that much sooner.

Listed below are seven of the most likely error codes you might encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you could fix it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can anticipate paying around $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware required to wrap up repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is detached from the system. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the problem is fixed.

Losing power to your Nest thermostat can be for numerous reasons. The wiring might have disconnected or become damaged, or a disconnection may have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician will examine electrical connections and wiring until they uncover the source of the problem.

e294 - Critical

Critical error code e294 shows up when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.

They’ll shut off the power and slowly check each wire, seeing to it that they are fully attached into the connector with the proper amount of exposed copper. When they locate the problem connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can show up when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Assuming the breakers are on, you can inspect a handful of other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step might be restoring enough power to find out if this specific error code is what you’re working with. You can detach the thermostat from its base and deliver power through a USB cable. If it reveals error code 195, you can continue to visually inspect 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 contact a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving 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. The technician should meticulously examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

While this error code isn’t critical, it may still keep 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 obtaining enough power. You can examine 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.

During 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 need to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 - Critical

Similar to error code e103, e104 is a critical error stemming 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 appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to switch the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience diagnosing and solving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This will sometimes be as simple as the breaker being switched off, but it could also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s best to speak with a local professional.