How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the easiest ways to perfect the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you can 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 present solutions that much quicker.

Here are seven of the most frequent error codes you could find on your Nest thermostat. We’ll explain the basics of each error code along with how you might solve it and the projected cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can anticipate paying between $75-$200 for repairs. This should also cover travel and labor costs on top of any specific hardware needed to wrap up 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 change to the backup battery system. The error message will continue to be displayed until the problem 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 may have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can check electrical connections and wiring until they locate the root of the problem.

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring has 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 ensure it’s not simply a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll detach the power and progressively look at each wire, ensuring they are fully inserted into the connector with the correct amount of uncovered copper. After they locate 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 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 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.

As this error can consume your thermostat’s battery, the first step might be providing enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power by using a USB cable. If it displays error code 195, you may continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will probably be best to contact a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician will cautiously 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.

n260

While this error code isn’t critical, it might still keep you from using the Nest thermostat like normal. Error code n260 concerns 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 inspect 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 may notice error code E297 show up. This can be remedied 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

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 could even be a fire hazard. If you see 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 in touch with a professional technician with the necessary experience identifying and solving electrical malfunctions.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This will sometimes be as straightforward as the breaker being turned off, but it may 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 none of them are loose or damaged. If nothing looks to be out of place, it’s time to speak with a local professional.