Operating a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make improvements. But as you may expect, it won’t work well or at all if you see an error code appear. The exact error code provides useful information about the source of the problem, something a trained technician can use to provide solutions that much faster.

Let’s consider seven of the most common error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could solve it and the projected cost to do so. Keep in mind that while the investment will ultimately depend on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should include travel and labor costs along with any specific parts necessary to complete repairs.

e298 – Critical

This critical error code is limited to newer 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 the screen until the problem is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection may have happened further along in your home’s electrical system. This might be the circuit breaker, fuse box or system switch. A professional technician should inspect electrical connections and wiring until they find the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should 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 examine the wiring diagram of the thermostat and start checking connectors.

They’ll disconnect the power and progressively inspect each wire, seeing to it that they are fully attached into the connector with the correct amount of uncovered copper. When they find the damaged 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 shut down and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will subsequently power down. In the event the breakers are on, you can check a couple of other places before consulting a professional technician.

Since this error can deplete your thermostat’s battery, the first step might be restoring enough power to figure out if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power with a USB cable. Assuming it presents error code 195, you should continue to visually inspect components like 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 get in touch with 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 receiving more power than needed. This may stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. Your technician should cautiously 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

Even though this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving enough 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 show up. This can be dealt with 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 originating from an overcurrent. If too much power is transported through the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to turn the power off as soon as you can. You can then get in touch with a professional technician with the proper experience identifying and fixing electrical issues.

e73 – Critical

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

This might be as simple 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 inspect the wires to make sure nothing is loose or damaged. If nothing looks to be out of place, it’s best to contact a local professional.