Installing a Nest thermostat is one of the easiest ways to optimize the daily 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 show up. The specific error code supplies useful information about the root of the problem, something a professional technician can use to offer solutions that much sooner.

Let’s consider seven of the most common error codes you could discover on your Nest thermostat. We’ll explain the basics of each error code along with how you can solve it and the projected cost to do so. Remember that while the investment will ultimately depend on the specific Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs as well as any specific components required to finish repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is disconnected from the system. As this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the problem is resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should check electrical connections and wiring until they locate 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 conduct a factory reset of your thermostat to make sure it’s not just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and gradually check each wire, making sure they are fully attached into the connector with the correct amount of exposed copper. Once they pinpoint the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is especially hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually power down. In the event the breakers are on, you can check a couple of other places before contacting a professional technician.

Since this error can drain your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re facing. You can disconnect the thermostat from its base and provide power through a USB cable. If it reveals 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 don’t find anything wrong with these components, it will likely be best to call a pro.

e103 – Critical

Another critical error code, e103 signifies 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 what is safe and normal. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. The technician will carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might 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 the absence of one can block your Nest from getting sufficient 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 need a Nest Power Connector.

During installation of a Nest Power Connector, you might notice error code E297 appear. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is 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 stemming from an overcurrent. If excess power is being delivered inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to guard against electrical damage, it’s recommended to shut the power off straightaway. You can then contact a professional technician with the necessary experience detecting and fixing electrical issues.

e73 – Critical

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

This will sometimes be as simple as the breaker being switched off, but it may also be something with the wiring. After shutting 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 appears to be out of place, it’s best to contact a local professional.