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

Listed below are seven of the most common error codes you might find on your Nest thermostat. We’ll explain the basics of each error code as well as how you could fix it and the estimated cost to do so. Don’t forget that while the investment will ultimately be dependent on the exact Nest model, you can count on paying between $75-$200 for repairs. This should also cover travel and labor costs on top of any specific components necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and appears when the power is disconnected from the system. Since this is a critical power error, the thermostat will swap 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 could have disconnected or become damaged, or a disconnection might have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician will check electrical connections and wiring until they uncover 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, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not merely a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and progressively check 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 show up when the weather outside is particularly hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally power down. Presuming the breakers are on, you can search a couple of other places before calling a professional technician.

Because this error can consume your thermostat’s battery, the first step might be supplying enough power to determine if this specific error code is what you’re dealing with. You can separate the thermostat from its base and provide power by using a USB cable. In the event it displays error code 195, you may continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can’t detect anything wrong with these components, it will likely be best to call a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue 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 may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician can meticulously examine 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

Although this error code isn’t critical, it may still keep you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from obtaining sufficient power. You can check 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.

Due to installation of a Nest Power Connector, you might notice error code E297 appear. 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

Similar to error code e103, e104 is a critical error stemming from an overcurrent. If too much power is sent through the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code show up on your Nest thermostat and want to protect from electrical damage, it’s a good idea to switch the power off as soon as you can. You can then get a hold of a professional technician with the necessary experience identifying and solving electrical damage.

e73 – Critical

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

This will sometimes be as simple as the breaker being shut off, but it may also be an issue with the wiring. After turning 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 seems to be out of place, it’s best to contact a local professional.