How to Resolve These Seven Error Codes on Your Nest Thermostat

Using a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make improvements. But as you can expect, it won’t work properly or at all if you see an error code on the display. The exact error code offers useful information about the underlying problem, something a professional technician can use to present solutions that much sooner.

Here are seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you might solve 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 anticipate paying between $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware needed to wrap up repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears 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 continue to be displayed until the issue is fixed.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection might have happened further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician should examine 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 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 merely a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and progressively check each wire, seeing to it that they are fully inserted into the connector with the correct amount of exposed copper. When they find the problem connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally turn off. Assuming the breakers are on, you can examine a handful of other places before contacting a professional technician.

As this error can drain your thermostat’s battery, the first step might be supplying enough power to find out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and supply power by using a USB cable. If it reveals error code 195, you may continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can’t uncover anything wrong with these components, it will probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than necessary. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician will meticulously 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.

n260

While this error code isn’t critical, it can still prevent you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving sufficient 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 can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead need 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 transported using the Nest’s wiring, it can damage internal components and may 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 suggested to shut the power off straightaway. You can then contact a professional technician with the necessary experience diagnosing and resolving electrical problems.

e73 – Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power.

This may be as straightforward as the breaker being turned 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 nothing is loose or damaged. If nothing looks to be out of place, it’s time to contact a local professional.