Operating a Nest thermostat is one of the easiest ways to perfect the daily schedule of your comfort system. This smart thermostat can be taught your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code appear. The exact error code offers useful information about the underlying problem, something a knowledgeable technician can use to present solutions that much quicker.
Here are seven of the most likely error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could address it and the projected cost to do so. Don't forget that while the costs will ultimately be dependent on the exact Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts needed to wrap up repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and shows up when the power is detached 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 numerous reasons. The wiring might have disconnected or become damaged, or a disconnection might have occurred further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician will 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 make sure it’s not just a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.
They’ll detach the power and gradually check each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. When they locate the malfunctioning connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can appear when the weather outside is particularly 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 depletes and the thermostat will finally power down. Assuming the breakers are on, you can check a handful of other places before calling a professional technician.
Because this error can consume your thermostat’s battery, the first step may 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 supply power by using a USB cable. If 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 don’t detect anything wrong with these components, it will probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This can stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. The technician can meticulously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
While this error code isn’t critical, it might still prevent you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing 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 adapt the wiring itself if there is. If not, you need a Nest Power Connector.
Due to installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Like error code e103, e104 is a critical error originating from an overcurrent. If excessive power is being delivered through the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s suggested to turn the power off as soon as you can. You can then contact a professional technician with the proper experience diagnosing and fixing electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This will sometimes be as easy as the breaker being switched off, but it may also be a problem 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.