Using a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make changes. But as you can expect, it won’t work correctly or at all if you see an error code on the display. The exact error code provides useful information about the root of the problem, something a professional technician can use to offer solutions that much faster.

Here are seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll review the basics of each error code on top of how you can address it and the projected cost to do so. Remember that while the price will ultimately hinge on the exact Nest model, you can count on paying around $75-$200 for repairs. This should include things like travel and labor costs along with any specific hardware needed to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is disconnected from the system. As this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the issue is dealt with.

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

e294 – Critical

Critical error code e294 is displayed 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 conduct 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 begin inspecting connectors.

They’ll disconnect the power and gradually look at each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. When they pinpoint the problem 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 break down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually shut down. Assuming the breakers are on, you can check a few other places before calling a professional technician.

As this error can consume your thermostat’s battery, the first step may be restoring 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 with a USB cable. Assuming it presents error code 195, you should continue to visually examine 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 suggests an electrical problem with your Nest thermostat. More specifically, e103 will 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 through a defective connection in the thermostat. The technician needs to cautiously 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

Although this error code isn’t critical, it could still stop you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having 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.

With 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 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 excessive power is transported inside the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s recommended to shut the power off as soon as you can. You can then get in touch with 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 might be as easy as the breaker being turned off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s best to contact a local professional.