Installing a Nest thermostat is one of the most convenient ways to optimize the day-to-day schedule of your heating and cooling. 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 specific error code supplies useful information about the root of the problem, something a knowledgeable technician can use to present solutions that much sooner.

Let’s consider seven of the most likely error codes you could encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you could fix it and the estimated cost to do so. Keep in mind that while the investment will ultimately be dependent on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to finish repairs.

e298 – Critical

This critical error code is limited to newer 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 continue to be displayed until the problem is fixed.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection could have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician should examine 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 should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.

They’ll detach the power and progressively look at each wire, seeing to it that they are fully placed into the connector with the proper amount of exposed copper. Once they pinpoint the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear 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 subsequently shut down. Presuming the breakers are on, you can check a handful of other places before calling a professional technician.

As this error can consume your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re working with. You can disconnect the thermostat from its base and provide power by using 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 don’t detect anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This can stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. Your technician needs to carefully inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it can 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 inspect the Nest’s C connector for the presence of a C wire and adjust 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 show up. This can be dealt with 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

Similar to error code e103, e104 is a critical error that’s the result of an overcurrent. If excess power is sent using the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to turn the power off as soon as possible. You can then contact a professional technician with the proper experience detecting and resolving electrical issues.

e73 – Critical

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

This will sometimes be as simple as the breaker being switched off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually examine the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s time to contact a local professional.