Using a Nest thermostat is one of the most convenient ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. But as you may expect, it won’t work well or at all if you see an error code on the display. The exact error code supplies useful information about the underlying problem, something a professional technician can use to provide solutions that much quicker.
Here are seven of the most common error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code on top of how you can fix it and the projected cost to do so. Keep in mind that while the price will ultimately hinge on the exact Nest model, you can anticipate paying between $75-$200 for repairs. This should also cover travel and labor costs along with any specific components necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and appears when the power is detached from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue is resolved.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have happened further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician will inspect 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 should be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete 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 begin inspecting connectors.
They’ll disconnect the power and gradually look at each wire, ensuring they are fully inserted into the connector with the proper amount of exposed copper. After they find the problem connector, it can be swapped for a new one.
e195 - Critical
This critical error code can show up when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will eventually power down. Assuming the breakers are on, you can check a handful of other places before consulting a professional technician.
Since 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 working with. You can separate the thermostat from its base and provide power by using a USB cable. In the event it reveals error code 195, you can continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will probably be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting 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. A technician should carefully examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 pertains to 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.
During installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have 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 originating from an overcurrent. If excessive power is transported using 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 protect from electrical damage, it’s recommended to shut the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience detecting and resolving electrical damage.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This may be as simple as the breaker being shut off, but it may also be a problem with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s a good idea to contact a local professional.