Installing 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 adjustments. But as you might expect, it won’t work correctly or at all if you see an error code on the display. The specific error code offers useful information about the root of the problem, something a knowledgeable technician can use to provide solutions that much quicker.
Here are seven of the most likely error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might address it and the projected cost to do so. Keep in mind that while the price will ultimately depend on the precise Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific parts required to finish repairs.
e298 - Critical
This critical error code is limited to new 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 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 occurred further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can check electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring should 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 issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.
They’ll disconnect the power and slowly inspect each wire, making sure they are fully inserted into the connector with the proper amount of exposed copper. After they locate the damaged 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 break down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently power down. Presuming the breakers are on, you can search a couple of other places before consulting a professional technician.
Since this error can deplete your thermostat’s battery, the first step could be providing 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 supply power by using a USB cable. Assuming it reveals error code 195, you may continue to visually inspect 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 call a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than necessary. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. The technician can cautiously investigate and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
While this error code isn’t critical, it might 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 missing 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 adjust the wiring itself if there is. If not, you need a Nest Power Connector.
Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 that's the result of an overcurrent. If too much power is being delivered inside the Nest’s wiring, it could 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 suggested to switch the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience diagnosing 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 easy as the breaker being switched off, but it could also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s best to get in touch with a local professional.