Installing a Nest thermostat is one of the easiest ways to improve the day-to-day schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make changes. But as you may expect, it won’t work correctly or at all if you see an error code on the display. The specific error code provides useful information about the root of the problem, something a professional technician can use to provide solutions that much quicker.
Here are seven of the most likely error codes you may find on your Nest thermostat. We’ll review the basics of each error code on top of how you might solve it and the estimated cost to do so. Keep in mind that while the price will ultimately depend 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 hardware needed to finish 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. As this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is resolved.
Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection could have happened further along in your home's electrical system. This might 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 appears when your Nest thermostat’s wiring should 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 simply a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.
They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. Once they pinpoint the malfunctioning connector, it can be swapped for a new one.
e195 - Critical
This critical error code can surface 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 drains and the thermostat will subsequently shut down. In the event the breakers are on, you can check a few other places before calling a professional technician.
Because this error can consume your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re working with. You can detach the thermostat from its base and deliver power with a USB cable. If it displays error code 195, you can continue to visually check components like 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 likely be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 signifies 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 necessary. This can stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. A technician will meticulously inspect and test the Nest’s electrical system to figure out where the power is surging or why the thermostat is convinced 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 concerns the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving 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’ll need a Nest Power Connector.
Due to installation of a Nest Power Connector, you may notice error code E297 appear. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 too much power is being delivered through the Nest’s wiring, it can 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 a good idea to turn the power off as soon as possible. You can then contact a professional technician with the appropriate experience diagnosing and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This might be as easy as the breaker being switched off, but it may also be an issue with the wiring. After turning 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 looks to be out of place, it’s a good idea to speak with a local professional.