Operating a Nest thermostat is one of the most convenient ways to perfect the day-to-day schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. 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 provides useful information about the root of the problem, something a trained technician can use to provide solutions that much quicker.

Here are seven of the most frequent error codes you may encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you might address it and the projected cost to do so. Remember that while the costs will ultimately be dependent on the exact Nest model, you can expect to pay between $75-$200 for repairs. This should include travel and labor costs on top of any specific parts needed to complete 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. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is dealt with.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A knowledgeable technician should inspect electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and slowly check each wire, ensuring they are fully attached into the connector with the proper amount of uncovered copper. Once they find the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually turn off. Assuming the breakers are on, you can examine a handful of other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power through a USB cable. Assuming it presents error code 195, you should continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can’t 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 can refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This can stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician will carefully investigate 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

Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from receiving adequate power. You can examine 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.

Due to 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 is already installed, you’ll instead need 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 too much power is transported inside the Nest’s wiring, it can 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 a good idea to switch the power off straightaway. You can then get a hold of a professional technician with the appropriate experience identifying and resolving electrical issues.

e73 – Critical

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

This could 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 examine the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s time to contact a local professional.