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 recognize 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 provides useful information about the underlying problem, something a trained technician can use to offer solutions that much quicker.
Let's consider seven of the most frequent error codes you could find on your Nest thermostat. We’ll explain the basics of each error code on top of how you could address it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the specific 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 hardware necessary to finish repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and appears when the power is shut off. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the problem is resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can examine electrical connections and wiring until they uncover the root of the problem.
e294 - Critical
Critical error code e294 shows up when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.
They’ll shut off the power and progressively inspect each wire, seeing to it that they are fully attached into the connector with the proper amount of exposed copper. When they find the malfunctioning connector, it can be exchanged 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 giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. In the event the breakers are on, you can search a handful of other places before contacting a professional technician.
Because this error can drain your thermostat’s battery, the first step could 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 provide power by using a USB cable. If it reveals error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. A technician will cautiously examine 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 can still prevent 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 the absence of one can block your Nest from obtaining enough power. You can inspect 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 be displayed. This can be dealt with 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 stemming from an overcurrent. If excessive power is sent inside 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 turn the power off as soon as possible. You can then contact a professional technician with the necessary experience identifying and solving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it indicates 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 shutting 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 get in touch with a local professional.