Using a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make improvements. But as you can expect, it won’t work well or at all if you see an error code on the display. The specific error code offers useful information about the underlying problem, something a professional technician can use to offer solutions that much faster.

Here are seven of the most common error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code along with how you can fix it and the approximate cost to do so. Keep in mind that while the price will ultimately be dependent on the specific Nest model, you can count on paying around $75-$200 for repairs. This should include travel and labor costs along with any specific parts needed to finish 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. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on the screen 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 could have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can examine electrical connections and wiring until they uncover the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring has 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 just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.

They’ll detach the power and slowly inspect each wire, seeing to it that they are fully inserted into the connector with the correct amount of bare copper. After they find the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally shut down. In the event the breakers are on, you can search a handful of other places before contacting a professional technician.

Since this error can consume your thermostat’s battery, the first step may 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. In the event it displays error code 195, you may continue to visually check components like 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 will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This will sometimes stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. A technician can meticulously 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

Even though this error code isn’t critical, it may still stop 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 not having one can block your Nest from obtaining adequate 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 appear. 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

Similar to error code e103, e104 is a critical error stemming from an overcurrent. If excess power is sent through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s suggested to shut the power off as soon as possible. You can then get a hold of a professional technician with the necessary experience identifying and fixing electrical damage.

e73 – Critical

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

This will sometimes be as simple as the breaker being shut off, but it may also be something 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 appears to be out of place, it’s best to speak with a local professional.