Here's What These 7 Nest Thermostat Error Codes Mean

Using a Nest thermostat is one of the easiest ways to optimize the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make changes. But as you might expect, it won’t work properly or at all if you see an error code on the display. The exact error code offers useful information about the source of the problem, something a professional technician can use to provide solutions that much quicker.

Let’s consider seven of the most frequent error codes you might encounter 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. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware required to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on the screen until the problem is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician will check electrical connections and wiring until they locate 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 ensure it’s not simply a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and progressively check each wire, making sure they are fully inserted into the connector with the proper amount of uncovered copper. After they pinpoint the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can inspect a couple of other places before consulting a professional technician.

Since this error can deplete your thermostat’s battery, the first step may be supplying enough power to determine if this specific error code is what you’re working with. You can detach the thermostat from its base and deliver power by using a USB cable. In the event it presents error code 195, you can 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 problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. The technician will cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate power. You can inspect the Nest’s C connector for the presence of a C wire and modify 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 be displayed. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 excess power is being delivered using the Nest’s wiring, it may 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 guard against electrical damage, it’s suggested to turn the power off straightaway. You can then contact a professional technician with the proper experience identifying and resolving electrical malfunctions.

e73 – Critical

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

This may be as easy 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 inspect the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s time to get in touch with a local professional.