close up of a nest smart thermostat

Operating a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make improvements. But as you might expect, it won’t work well or at all if you see an error code show up. The specific error code supplies useful information about the underlying problem, something a professional technician can use to offer solutions that much sooner.

Let’s consider seven of the most likely error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you can fix it and the projected cost to do so. Keep in mind that while the investment will ultimately be dependent on the exact Nest model, you can anticipate paying between $75-$200 for repairs. This should also cover travel and labor costs along with any specific components necessary to finish 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. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue 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 might have appeared further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician should examine electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 is displayed 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 just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and progressively look at each wire, making sure they are fully attached into the connector with the proper amount of uncovered copper. Once they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently power 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 supplying enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power through a USB cable. If it displays error code 195, you can continue to visually inspect components including 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 call 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 experiencing more power than necessary. This may stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. A technician will meticulously inspect and test the Nest’s electrical system to determine 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 stop you from using the Nest thermostat how you prefer to. 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 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 need a Nest Power Connector.

During 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 be required 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 that’s the result of an overcurrent. If too much power is transported using the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience diagnosing and resolving electrical problems.

e73 – Critical

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

This will sometimes be as straightforward as the breaker being switched 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 nothing is loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.