Installing a Nest thermostat is one of the easiest ways to improve the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work well or at all if you see an error code show up. The specific error code provides useful information about the source of the problem, something a professional technician can use to provide solutions that much faster.
Listed below are seven of the most common error codes you might find on your Nest thermostat. We’ll review the basics of each error code on top of how you could fix it and the estimated cost to do so. Don't forget that while the costs will ultimately hinge on the specific Nest model, you can count on paying about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific components needed to complete repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and shows up when the power is detached from the system. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will continue to be displayed until the issue is dealt with.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection may have occurred further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician will examine electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 shows up 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 just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start inspecting connectors.
They’ll detach the power and gradually check each wire, seeing to it that they are fully placed into the connector with the proper amount of uncovered copper. After they locate the damaged connector, it can be swapped 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 sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually turn off. In the event the breakers are on, you can inspect a couple of other places before calling a professional technician.
Because this error can consume your thermostat’s battery, the first step could be providing enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and provide power through a USB cable. If it reveals error code 195, you may 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 malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. A technician needs to carefully inspect 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 stop 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 obtaining adequate power. You can inspect the Nest’s C connector for the presence of a C wire and modify 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 resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Like error code e103, e104 is a critical error stemming from an overcurrent. If too much power is being delivered through the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s suggested to turn the power off straightaway. You can then get a hold of a professional technician with the necessary experience identifying and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This might be as straightforward as the breaker being shut off, but it could also be a problem with the wiring. After turning 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 seems to be out of place, it’s time to get in touch with a local professional.