Using a Nest thermostat is one of the best ways to optimize the daily schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make adjustments. But as you can expect, it won’t work properly 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 trained technician can use to present solutions that much sooner.

Let’s consider seven of the most frequent error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might address it and the approximate cost to do so. Remember that while the costs will ultimately depend on the precise Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts necessary to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is detached from the system. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the issue is dealt with.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection could have occurred further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician should inspect electrical connections and wiring until they find the root of the problem.

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not merely a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start looking at connectors.

They’ll detach the power and progressively check each wire, making sure they are fully inserted into the connector with the proper amount of exposed copper. When they find the problem connector, it can be swapped 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 sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally power down. In the event the breakers are on, you can check a couple of other places before consulting a professional technician.

Since this error can deplete your thermostat’s battery, the first step may be providing enough power to find out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and provide power with a USB cable. In the event it reveals error code 195, you should continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it’s maybe best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. A technician should carefully examine and test the Nest’s electrical system to understand 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 stop you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving sufficient 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 can get a Nest Power Connector.

During installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 excess power is sent using the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s recommended to switch the power off as soon as you can. You can then contact a professional technician with the appropriate experience diagnosing and resolving electrical malfunctions.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it can also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s a good idea to contact a local professional.