Installing a Nest thermostat is one of the easiest ways to optimize the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make adjustments. But as you may expect, it won’t work correctly or at all if you see an error code show up. The specific error code supplies useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much sooner.
Let's consider seven of the most likely error codes you might encounter on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might solve it and the estimated cost to do so. Remember that while the costs will ultimately hinge on the specific Nest model, you can count on paying between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific hardware necessary to finish repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and is displayed when the power is detached 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 the screen until the problem is fixed.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection may have happened further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician can check 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 has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll detach the power and progressively check each wire, making sure they are fully inserted into the connector with the proper amount of exposed copper. Once they find the problem connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can show up when the weather outside is particularly hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Presuming the breakers are on, you can search a couple of other places before contacting a professional technician.
As this error can drain your thermostat’s battery, the first step may be supplying enough power to find out if this specific error code is what you’re facing. You can disconnect the thermostat from its base and provide power by using a USB cable. If it reveals error code 195, you should continue to visually examine 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 will likely be best to call a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than needed. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician should meticulously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.
While this error code isn’t critical, it may still stop 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 the absence of one can block your Nest from getting enough power. You can examine 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 dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was 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 originating from an overcurrent. If excessive power is being delivered 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 switch the power off as soon as possible. You can then get a hold of a professional technician with the proper experience identifying and fixing electrical issues.
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 shut 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 check the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s a good idea to contact a local professional.