Operating a Nest thermostat is one of the most convenient ways to optimize the day-to-day schedule of your HVAC 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 exact error code supplies useful information about the underlying problem, something a professional technician can use to present solutions that much sooner.

Here are seven of the most likely error codes you might discover on your Nest thermostat. We’ll review the basics of each error code on top of how you could address it and the projected cost to do so. Keep in mind that while the investment will ultimately be dependent on the precise Nest model, you can expect to pay about $75-$200 for repairs. This should include travel and labor costs as well as any specific components needed 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 swap to the backup battery system. The error message will continue to be displayed until the problem is dealt with.

Losing power to your Nest thermostat can be for numerous reasons. The wiring might have disconnected or become damaged, or a disconnection may have happened further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician can check 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 complete a factory reset of your thermostat to make sure it’s not merely a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and progressively inspect each wire, ensuring they are fully inserted into the connector with the proper amount of exposed copper. Once they locate the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is severely 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 subsequently shut down. Presuming the breakers are on, you can examine a few other places before calling a professional technician.

Since this error can drain your thermostat’s battery, the first step might be providing 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 with a USB cable. Assuming it presents error code 195, you may continue to visually check 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 will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than necessary. This will sometimes stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. The technician can 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

Although this error code isn’t critical, it may still keep you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from getting adequate power. You can examine the Nest’s C connector for the presence of a C wire and adapt 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 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 stemming from an overcurrent. If excessive power is transported using the Nest’s wiring, it can 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 take steps to prevent electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience identifying and solving electrical issues.

e73 – Critical

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

This could be as straightforward as the breaker being shut off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s best to speak with a local professional.