Using a Nest thermostat is one of the easiest ways to optimize the daily schedule of your comfort system. This smart thermostat can learn your preferences and automatically make improvements. But as you may expect, it won’t work well or at all if you see an error code appear. The precise error code offers useful information about the source of the problem, something a trained technician can use to present solutions that much faster.

Here are seven of the most likely error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code as well as how you can fix it and the approximate cost to do so. Don’t forget that while the investment will ultimately be dependent on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is detached 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 issue is resolved.

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 your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician should examine electrical connections and wiring until they find the root of the problem.

e294 – Critical

Critical error code e294 shows up 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 conduct a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll shut off the power and progressively check each wire, making sure they are fully attached into the connector with the proper amount of bare copper. Once they locate the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is especially 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 drains and the thermostat will finally shut down. In the event the breakers are on, you can check a few other places before contacting a professional technician.

As this error can drain your thermostat’s battery, the first step might be restoring enough power to determine if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and provide power with a USB cable. In the event it displays error code 195, you should 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’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. The technician should 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 can still prevent you from using the Nest thermostat how you prefer 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 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.

With installation of a Nest Power Connector, you may notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already 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 that’s the result of an overcurrent. If too much power is transported through the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s recommended to turn the power off straightaway. You can then get in touch with a professional technician with the appropriate experience identifying and fixing electrical issues.

e73 – Critical

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

This will sometimes be as straightforward as the breaker being switched off, but it may also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.