How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your heating and cooling. 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 show up. The precise error code offers useful information about the source of the problem, something a professional technician can use to offer solutions that much faster.

Listed below are seven of the most frequent error codes you might discover 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 count on paying about $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to complete repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up 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 remain on display until the problem is resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring might have disconnected or become damaged, or a disconnection may have occurred further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician should examine electrical connections and wiring until they uncover the root of the problem.

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not merely a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start checking connectors.

They’ll detach the power and slowly 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 malfunctioning connector, it can be replaced for a new one.

e195 - Critical

This critical error code can surface when the weather outside is severely 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 eventually turn off. In the event the breakers are on, you can search a few other places before calling a professional technician.

Because this error can deplete your thermostat’s battery, the first step could be restoring enough power to find out if this specific error code is what you’re working with. You can detach the thermostat from its base and provide power through a USB cable. If it presents error code 195, you should continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it's maybe best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This can stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. Your technician needs to meticulously investigate and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might still prevent 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 obtaining adequate power. You can inspect 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 may notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead need 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 stemming from an overcurrent. If excessive power is transported using the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to switch the power off as soon as you can. You can then contact a professional technician with the necessary experience identifying and resolving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This might be as straightforward as the breaker being shut off, but it may also be something with the wiring. After shutting 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 looks to be out of place, it’s time to get in touch with a local professional.