Operating a Nest thermostat is one of the easiest ways to perfect the everyday schedule of your comfort system. This smart thermostat can learn 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 show up. The specific error code offers useful information about the underlying problem, something a knowledgeable technician can use to offer solutions that much sooner.

Here are seven of the most likely error codes you could 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 projected cost to do so. Remember that while the costs will ultimately depend on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific components necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is disconnected 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 display until the issue is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection might have happened further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician should inspect electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform 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 begin looking at connectors.

They’ll shut off the power and slowly inspect each wire, ensuring they are fully inserted into the connector with the proper amount of bare copper. Once they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is especially hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will subsequently shut down. In the event the breakers are on, you can inspect a few other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step may be restoring 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 deliver power by using a USB cable. In the event it presents error code 195, you may continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it will likely be best to call 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 getting more power than necessary. This can stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician can meticulously 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

Although this error code isn’t critical, it can 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 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’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you might notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead be required 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 that’s the result of an overcurrent. If excess power is transported using the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s recommended to turn the power off as soon as you can. You can then get a hold of a professional technician with the appropriate experience identifying and resolving electrical damage.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it may also be an issue with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s best to speak with a local professional.