E298 code on 9 month old Nest thermostat

[Kkovacs11]

Receiving a E298 code. Nothing has changed. No wires have been tampered with, all circuit breakers are on. For the past day the system goes on and the shuts off and says no power. Batteries have been changed and this did not help. Can the Nest be defective? 

[zoeuvre]

Hi Kkovacs11, 

Uh-oh! Try these: 

1. Make sure the breakers are on. 
2. If you used AC recently, check your system’s drip pan or drain tubes (skip this step if you only have a heating system). 
3. Check the condition of the HVAC fuse.
   • Turn off the main power to the HVAC system at the breaker box. Note: The HVAC system can have multiple breakers, so make sure the customer turns them all off.
   • Check the furnace and fan and make sure there are no lights that might indicate the system still has power. Note: If there are still lights on the furnace or fan, the system might still have power, and you need to turn off the main power to their home at the breaker.
   • Search for the HVAC fuse. It’s usually on the furnace control board. Note: If you need help to find their control board, check your owner’s manual. Fuses can be different for each type of system. You might find a small U-shaped fuse with a number 3 label and is pink or purple colored. You might also find a round fuse. 
   • Remove and inspect the fuse for damage. If the fuse seems burnt or has discoloration, consider a fuse replacement. To learn more about fuse replacement, consult the user guide for the HVAC system or contact a Nest Pro.
   • Make sure to reattach any panels on the furnace. Note: The furnace might not work if the customer doesn't reattach the panels.
   • If you're not comfortable checking the HVAC fuse, the replacement fuse doesn’t fix the issue, or the you can’t find the fuse, proceed to the next step.
4. Check you have an energy savings box. Some utility companies install boxes that cut off the power during high-demand (peak) times. These energy savings boxes can cause the error.
   
   • Check if there’s an energy savings box in your house.
     1. Search for an energy savings box near the electric meter (possibly near their air conditioner).
     2. Search for a small box with 2 lights on it (one light is red, the other is usually green). This box allows the utility company to cycle the your air conditioner off and on during certain peak times of the day.
   • If you have an energy savings box:
     1. Wait an hour or two for the rush hour to end, and then check if the error disappears.
     2. If the error disappears, contact their utility company, landlord, and/or Homeowners Association (HOA) for details about the program and your home's participation in it.
   • If you doesn’t have an energy savings box, proceed to the next step.
5. Check your air filter. You HVAC system needs to have a good airflow to work properly. A clog in the air filter can limit how much air flows over the cooling coils. If the clog persists, the cooling coils can freeze and cause your system to shut off.
6. Find your HVAC system’s air filter. The air filter is usually behind a grate in the hallway.
   • Check your walls and ceiling.
   • If you can’t find the air filter, search for it inside the furnace near the fan.
7. If the air filter seems dirty or there seems to be a clog, replace the filter with a new one. If the issue is because of frozen cooling coils, you need to wait a while for the HVAC system to thaw before they can use it again.

Let us know how it goes.

Best,

Zoe