Installing a Nest thermostat is one of the easiest ways to optimize the daily schedule of your comfort system. This smart thermostat can be taught 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 on the display. The specific error code provides useful information about the source of the problem, something a professional technician can use to present solutions that much quicker.
Let's consider seven of the most likely error codes you could discover on your Nest thermostat. We’ll review the basics of each error code on top of how you might fix it and the projected cost to do so. Don't forget that while the costs will ultimately depend on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific components required to complete repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is detached from the system. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen 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 could have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician will inspect electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, you’ll need the technician 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 examine the wiring diagram of the thermostat and begin inspecting connectors.
They’ll shut off the power and slowly inspect each wire, seeing to it that they are fully placed into the connector with the correct amount of uncovered copper. Once they locate the malfunctioning 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 shut down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will subsequently power down. Presuming the breakers are on, you can check a few other places before calling a professional technician.
As this error can deplete your thermostat’s battery, the first step could be providing enough power to find out if this specific error code is what you’re working with. You can detach the thermostat from its base and supply power with a USB cable. If it displays error code 195, you can continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can't detect anything wrong with these components, it will likely be best to contact a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 may 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 thanks to a defective connection in the thermostat. The technician can cautiously investigate and test the Nest’s electrical system to determine 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 keep you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate 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 may notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is 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 stemming from an overcurrent. If excessive power is sent through the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you see this error code appear 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 in touch with a professional technician with the proper experience detecting and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This could be as straightforward as the breaker being switched off, but it may also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s time to get in touch with a local professional.