Operating a Nest thermostat is one of the best ways to perfect the day-to-day schedule of your comfort system. This smart thermostat can learn your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code show up. The precise error code offers useful information about the root of the problem, something a professional technician can use to present solutions that much sooner.
Listed below are seven of the most likely error codes you may find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you could fix it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the precise Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs on top of any specific components needed to complete repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is shut off. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will continue to be displayed until the problem is fixed.
Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection may have happened further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician will examine electrical connections and wiring until they find the source of the problem.
e294 - Critical
Critical error code e294 appears 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 make sure it’s not just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.
They’ll shut off the power and gradually look at each wire, seeing to it that they are fully placed into the connector with the proper amount of uncovered copper. Once they locate the damaged connector, it can be swapped for a new one.
e195 - Critical
This critical error code can appear when the weather outside is especially hot. The HVAC system can break down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally power down. In the event the breakers are on, you can check a few other places before contacting a professional technician.
As this error can consume your thermostat’s battery, the first step may be restoring enough power to find out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and provide power with a USB cable. In the event it displays error code 195, you may continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it's maybe 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 getting more power than necessary. This will sometimes stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. A technician will 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.
Even though this error code isn’t critical, it can still prevent 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 getting adequate power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.
During installation of a Nest Power Connector, you might notice error code E297 show up. 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
Similar to error code e103, e104 is a critical error stemming from an overcurrent. If excess power is being delivered through the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to guard against electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience diagnosing and resolving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This will sometimes be as easy as the breaker being shut off, but it may also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.