Operating a Nest thermostat is one of the best ways to perfect the daily 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 well or at all if you see an error code appear. The exact error code offers useful information about the source of the problem, something a knowledgeable technician can use to provide solutions that much faster.
Let's consider seven of the most frequent error codes you may find on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you can address it and the estimated cost to do so. Remember that while the price will ultimately hinge on the precise Nest model, you can count on paying around $75-$200 for repairs. This should include things like travel and labor costs as well as any specific hardware necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to newer 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 remain on the screen until the issue is resolved.
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 appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician can check electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not simply a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start checking connectors.
They’ll detach the power and progressively look at each wire, seeing to it that they are fully attached into the connector with the correct amount of exposed copper. After they pinpoint the problem connector, it can be swapped 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 delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally turn off. Assuming the breakers are on, you can search a couple of other places before contacting a professional technician.
As this error can deplete your thermostat’s battery, the first step might be restoring enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power by using a USB cable. Assuming it presents error code 195, you may continue to visually check 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 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 necessary. This can stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. The technician will meticulously investigate and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Although this error code isn’t critical, it may still keep 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 missing one can block your Nest from obtaining enough power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.
Due to installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is 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 stemming from an overcurrent. If too much power is being delivered inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to switch the power off straightaway. You can then contact a professional technician with the proper experience diagnosing and solving electrical damage.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This may be as simple as the breaker being switched off, but it may also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s best to speak with a local professional.