Installing a Nest thermostat is one of the best ways to optimize the everyday schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work correctly or at all if you see an error code appear. The exact error code offers useful information about the underlying problem, something a knowledgeable technician can use to present solutions that much faster.

Here are seven of the most likely error codes you might find on your Nest thermostat. We’ll explain the basics of each error code on top of how you might address it and the projected cost to do so. Remember that while the costs will ultimately depend on the exact Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs as well as any specific parts required to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is disconnected 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 the screen until the issue is resolved.

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

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not simply a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start checking connectors.

They’ll detach the power and slowly inspect each wire, making sure they are fully inserted into the connector with the proper amount of bare copper. Once they pinpoint the problem connector, it can be swapped for a new one.

e195 – Critical

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

As this error can deplete your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power through a USB cable. If it displays error code 195, you can continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it’s maybe best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than needed. This can stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician needs to 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

Although this error code isn’t critical, it may still prevent 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 missing 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 modify the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you might 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 have to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Just like error code e103, e104 is a critical error originating from an overcurrent. If excess power is transported inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off as soon as you can. You can then get a hold of a professional technician with the proper experience identifying and solving electrical issues.

e73 – Critical

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

This may be as easy as the breaker being turned off, but it can 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 appears to be out of place, it’s best to contact a local professional.