Installing a Nest thermostat is one of the most convenient ways to optimize the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make changes. But as you may expect, it won’t work well or at all if you see an error code appear. The specific error code offers useful information about the underlying problem, something a professional technician can use to provide solutions that much sooner.

Here are seven of the most likely error codes you could find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might address it and the projected cost to do so. Remember that while the investment will ultimately depend on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs along with any specific hardware needed to finish repairs.

e298 – Critical

This critical error code is limited to newer 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 change to the backup battery system. The error message will remain on display 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 might have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician will inspect electrical connections and wiring until they find 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 perform a factory reset of your thermostat to ensure it’s not simply a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.

They’ll shut off the power and slowly check each wire, ensuring they are fully placed into the connector with the proper amount of uncovered copper. After they find the problem 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 persists, the backup battery in your thermostat drains and the thermostat will eventually power down. Presuming the breakers are on, you can check a few other places before consulting a professional technician.

Because this error can drain your thermostat’s battery, the first step may be restoring enough power to determine if this specific error code is what you’re facing. You can detach the thermostat from its base and provide power through a USB cable. If it displays error code 195, you can continue to visually check components like 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’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. Your technician needs to meticulously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Although this error code isn’t critical, it can still keep you from using the Nest thermostat like normal. 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 enough power. You can inspect the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you need a Nest Power Connector.

With 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 was already 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 that’s the result of an overcurrent. If excess power is transported inside the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to switch the power off straightaway. You can then get a hold of a professional technician with the appropriate experience identifying and resolving electrical problems.

e73 – Critical

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

This may 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 check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s a good idea to speak with a local professional.