Using a Nest thermostat is one of the easiest ways to optimize the everyday schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make changes. But as you can expect, it won’t work well or at all if you see an error code on the display. The specific error code supplies useful information about the root of the problem, something a professional technician can use to present solutions that much faster.

Let’s consider seven of the most likely error codes you may encounter on your Nest thermostat. We’ll review the basics of each error code along with how you could solve it and the projected cost to do so. Remember that while the costs will ultimately hinge on the specific Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed 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 remain on the screen until the problem is resolved.

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 will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully attached into the connector with the correct amount of exposed copper. Once they pinpoint the damaged connector, it can be swapped for a new one.

e195 – Critical

This critical error code can surface when the weather outside is especially hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can examine a few other places before calling a professional technician.

Because 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 supply power by using a USB cable. If it displays error code 195, you should continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 may 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 thanks to a bad connection in the thermostat. Your technician will meticulously 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

Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat like normal. 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 inspect 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.

During installation of a Nest Power Connector, you might notice error code E297 be displayed. This can be resolved 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 inside the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s a good idea to shut the power off straightaway. You can then get a hold of a professional technician with the appropriate experience diagnosing and solving electrical problems.

e73 – Critical

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

This might be as straightforward as the breaker being shut off, but it could also be a problem 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 time to contact a local professional.