Using a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. But as you can expect, it won’t work correctly or at all if you see an error code on the display. The exact error code provides useful information about the root of the problem, something a trained technician can use to present solutions that much sooner.

Listed below are seven of the most frequent error codes you could discover on your Nest thermostat. We’ll explain the basics of each error code as well as how you can fix it and the estimated cost to do so. Remember that while the price will ultimately be dependent on the precise Nest model, you can count on paying around $75-$200 for repairs. This should include travel and labor costs as well as any specific parts needed to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and appears 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 issue is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection may have occurred further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician can 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 has 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 examine the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and gradually check each wire, ensuring they are fully inserted into the connector with the correct amount of uncovered copper. When they find the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually turn off. Presuming the breakers are on, you can check a handful of other places before contacting a professional technician.

Since this error can drain your thermostat’s battery, the first step could be restoring enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power through a USB cable. Assuming it displays error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you can’t uncover anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 can 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 because of a faulty connection in the thermostat. The technician will carefully investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

While 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 not having 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 adapt the wiring itself if there is. If not, you’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be remedied 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 excessive power is transported using the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s suggested to switch the power off as soon as possible. You can then contact a professional technician with the appropriate experience diagnosing and solving electrical malfunctions.

e73 – Critical

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

This may be as straightforward as the breaker being turned off, but it can also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine 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.