Operating a Nest thermostat is one of the most convenient ways to improve the daily schedule of your comfort system. This smart thermostat can be taught your preferences and automatically make adjustments. But as you might expect, it won’t work properly or at all if you see an error code appear. The precise error code provides useful information about the source of the problem, something a knowledgeable technician can use to provide solutions that much sooner.

Here are seven of the most common error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might solve it and the approximate cost to do so. Keep in mind that while the investment will ultimately depend on the specific Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware required to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and shows up 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 display until the issue is resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A knowledgeable technician will check electrical connections and wiring until they uncover the root 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 conduct a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and slowly inspect each wire, making sure they are fully attached into the connector with the proper amount of bare copper. Once they find the problem 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 break down and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will finally shut down. In the event the breakers are on, you can inspect a handful of other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step might be restoring enough power to determine if this specific error code is what you’re facing. You can detach the thermostat from its base and supply power through a USB cable. In the event it reveals error code 195, you can continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you can’t find anything wrong with these components, it will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting 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 needs to carefully examine 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 might still keep you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving adequate power. You can check the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be resolved 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 originating from an overcurrent. If too much power is sent through 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 guard against electrical damage, it’s suggested to shut the power off straightaway. You can then get a hold of a professional technician with the proper experience identifying and resolving electrical damage.

e73 – Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power.

This might be as easy as the breaker being shut off, but it could also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s a good idea to contact a local professional.