Using a Nest thermostat is one of the most convenient ways to perfect the everyday schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you can expect, it won’t work well or at all if you see an error code appear. The exact error code provides useful information about the source of the problem, something a professional technician can use to offer solutions that much faster.
Here are seven of the most likely error codes you could find on your Nest thermostat. We’ll explain the basics of each error code along with how you might address it and the projected cost to do so. Remember 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 needed to complete 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. Since 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 occurred further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician can check electrical connections and wiring until they find the source of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not simply a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll shut off the power and gradually inspect each wire, seeing to it that they are fully placed into the connector with the proper amount of uncovered copper. When they locate the damaged connector, it can be replaced 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 giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will finally turn off. In the event the breakers are on, you can search a few other places before consulting a professional technician.
Because this error can deplete your thermostat’s battery, the first step may be restoring enough power to figure out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and deliver power through a USB cable. In the event it reveals error code 195, you can continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it's maybe best to call a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. The technician needs to cautiously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.
While this error code isn’t critical, it could still keep you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving adequate power. You can check 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.
During 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 was already installed, you’ll instead have 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 too much power is being delivered using the Nest’s wiring, it could damage internal components and may 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 suggested to turn the power off straightaway. You can then get in touch with a professional technician with the proper experience identifying and resolving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This will sometimes be as straightforward as the breaker being switched off, but it may also be something with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s best to contact a local professional.