Using a Nest thermostat is one of the best ways to optimize the everyday schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you can expect, it won’t work well or at all if you see an error code on the display. The exact error code provides useful information about the root of the problem, something a professional technician can use to offer solutions that much sooner.
Here are seven of the most likely error codes you may encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you can fix it and the approximate cost to do so. Don't forget that while the price will ultimately hinge on the specific Nest model, you can count on paying around $75-$200 for repairs. This should include things like travel and labor costs along with any specific components necessary to complete repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. Because 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 resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician will check electrical connections and wiring until they find the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring should 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 just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.
They’ll shut off the power and progressively check each wire, seeing to it that they are fully placed into the connector with the correct amount of bare copper. After they pinpoint the damaged connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can appear when the weather outside is especially hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes 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.
Since this error can consume your thermostat’s battery, the first step may be restoring enough power to figure out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and provide power by using a USB cable. In the event it presents error code 195, you can continue to visually check 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 call a pro.
e103 - Critical
Another critical error code, e103 signifies 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 needed. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician should meticulously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat believes there’s an overcurrent problem.
While this error code isn’t critical, it might still keep you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining enough 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’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 remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required 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 that's the result of an overcurrent. If too much power is transported using the Nest’s wiring, it can damage internal components and can 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 recommended to shut the power off as soon as possible. You can then contact a professional technician with the proper experience diagnosing and fixing electrical damage.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This may be as straightforward as the breaker being switched off, but it may also be an issue with the wiring. After turning 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 looks to be out of place, it’s best to speak with a local professional.