Using a Nest thermostat is one of the most convenient ways to improve 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 properly or at all if you see an error code show up. The exact error code provides useful information about the underlying problem, something a professional technician can use to present solutions that much sooner.

Here are seven of the most common error codes you may encounter 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 be dependent on the specific Nest model, you can anticipate paying around $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts necessary to finish repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the problem 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 may have appeared further along in your home’s electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can check electrical connections and wiring until they uncover the root 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 perform a factory reset of your thermostat to make sure it’s not simply a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll shut off the power and progressively inspect each wire, ensuring they are fully attached into the connector with the correct amount of bare copper. Once they pinpoint 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 fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually power down. Presuming the breakers are on, you can check a few other places before calling a professional technician.

Since this error can drain your thermostat’s battery, the first step may be providing enough power to find out if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power with a USB cable. Assuming it displays error code 195, you can continue to visually inspect components like 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 will probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than needed. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. The technician should meticulously investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it could still prevent you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from getting enough power. You can examine 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 will sometimes notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already 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 originating from an overcurrent. If excessive power is sent through the Nest’s wiring, it can 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 a good idea to turn the power off as soon as you can. You can then get a hold of a professional technician with the proper experience diagnosing and solving electrical malfunctions.

e73 – Critical

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

This might be as simple as the breaker being turned off, but it can also be an issue with the wiring. After switching 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 looks to be out of place, it’s best to contact a local professional.