Operating a Nest thermostat is one of the best 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 properly or at all if you see an error code show up. The precise error code supplies useful information about the root of the problem, something a knowledgeable technician can use to present solutions that much sooner.
Here are seven of the most common error codes you might find on your Nest thermostat. We’ll review the basics of each error code as well as how you can fix it and the projected cost to do so. Don't forget that while the costs will ultimately be dependent on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should include travel and labor costs on top of any specific parts needed to wrap up repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is disconnected 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 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 might have appeared further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician should check electrical connections and wiring until they uncover the root of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring should 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 simply a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.
They’ll disconnect the power and gradually inspect each wire, making sure they are fully placed into the connector with the proper amount of uncovered copper. When they find the damaged connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is particularly hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally power down. Assuming the breakers are on, you can search a few other places before contacting a professional technician.
Because this error can drain your thermostat’s battery, the first step could 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 deliver power through a USB cable. If it reveals error code 195, you may continue to visually inspect components such as 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 get in touch with a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 will 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 thanks to a faulty connection in the thermostat. Your technician needs to carefully investigate 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.
While this error code isn’t critical, it may still prevent you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as the absence of 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 can get a Nest Power Connector.
With installation of a Nest Power Connector, you will sometimes notice error code E297 show up. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 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 pop up on your Nest thermostat and want to protect from electrical damage, it’s a good idea to shut the power off as soon as you can. You can then get in touch with a professional technician with the necessary experience detecting and solving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This will sometimes be as simple as the breaker being shut off, but it may also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s best to contact a local professional.