Installing a Nest thermostat is one of the most convenient ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make changes. But as you might expect, it won’t work properly or at all if you see an error code appear. The specific error code provides useful information about the underlying problem, something a trained technician can use to offer solutions that much quicker.
Here are seven of the most likely error codes you could find on your Nest thermostat. We’ll review the basics of each error code on top of how you could solve it and the estimated cost to do so. Remember that while the price will ultimately depend on the exact Nest model, you can expect to pay between $75-$200 for repairs. This should include travel and labor costs along with any specific hardware necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the problem 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 might have happened further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician should examine electrical connections and wiring until they find the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll detach the power and slowly check each wire, making sure they are fully inserted into the connector with the correct amount of exposed copper. Once they find 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 giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will subsequently turn off. Presuming the breakers are on, you can check a handful of other places before contacting a professional technician.
As this error can drain your thermostat’s battery, the first step may 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 with a USB cable. Assuming it reveals 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 don’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 issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. The technician will carefully investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.
While this error code isn’t critical, it could 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 the absence of one can block your Nest from getting adequate 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 might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required 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 that's the result of an overcurrent. If too much power is transported inside the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see 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 straightaway. You can then get in touch with a professional technician with the appropriate experience detecting and solving electrical damage.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This will sometimes be as easy as the breaker being turned off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s a good idea to contact a local professional.