Operating a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make adjustments. But as you might expect, it won’t work properly or at all if you see an error code on the display. The precise error code offers useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.
Let's consider seven of the most common error codes you might find on your Nest thermostat. We’ll explain the basics of each error code on top of how you might fix it and the estimated cost to do so. Keep in mind that while the costs will ultimately be dependent on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware needed to finish repairs.
e298 - Critical
This critical error code is limited to new 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 change to the backup battery system. The error message will continue to be displayed until the issue is fixed.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A certified 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 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 merely a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.
They’ll shut off the power and progressively look at each wire, seeing to it that they are fully inserted into the connector with the correct amount of uncovered copper. Once they pinpoint the damaged connector, it can be replaced for a new one.
e195 - Critical
This critical error code can show up when the weather outside is especially hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally turn off. In the event the breakers are on, you can check a few other places before calling a professional technician.
Since this error can deplete your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and provide power by using a USB cable. Assuming it reveals error code 195, you may 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 call a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. A technician should meticulously inspect and test the Nest’s electrical system to determine 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 can still prevent you from using the Nest thermostat how you prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving enough power. You can examine the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.
Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead need to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Just like error code e103, e104 is a critical error originating from an overcurrent. If excessive power is sent through the Nest’s wiring, it may damage internal components and may 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 suggested to shut the power off straightaway. 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 means that the Rc wire is not getting power. This may be as simple as the breaker being switched off, but it can also be something 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 speak with a local professional.