Operating a Nest thermostat is one of the most convenient ways to perfect the everyday schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you may expect, it won’t work properly or at all if you see an error code show up. The exact error code supplies useful information about the source of the problem, something a professional technician can use to offer solutions that much quicker.

Here are seven of the most common error codes you might encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can address it and the projected cost to do so. Keep in mind that while the price will ultimately depend on the exact Nest model, you can count on paying between $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware needed to finish repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is disconnected from the system. As 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 problem is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection could have happened further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician will examine electrical connections and wiring until they find the source of the problem.

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring has to 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 merely a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.

They’ll detach the power and gradually inspect each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. Once 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 particularly hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally power down. Presuming the breakers are on, you can check a couple of other places before contacting a professional technician.

Since this error can drain your thermostat’s battery, the first step might be supplying enough power to determine if this specific error code is what you’re working with. You can detach the thermostat from its base and provide power with a USB cable. Assuming it presents error code 195, you can continue to visually check components including 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 likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical problem 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 through a faulty connection in the thermostat. Your technician should meticulously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it might still stop you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from getting adequate power. You can check the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be resolved 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

Similar to error code e103, e104 is a critical error stemming from an overcurrent. If excess power is transported inside the Nest’s wiring, it can damage internal components and could 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 a good idea to turn the power off as soon as you can. You can then get a hold of a professional technician with the proper experience identifying and fixing electrical problems.

e73 – Critical

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

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