Nest E73

[Blondejem]

Power won’t turn on

[Patrick_Caezza]

The E73 error means there is no power detected to the Rc wire.

This can be caused in several ways.

• Bad wire
  • Turn off power to your system at the breaker box, fuse box or system switch. This helps prevent damage to your system and keeps you safe.
  • Pull off the thermostat display.
  • Check that all connectors with wires are down as pictured.
    • If they aren’t, re-insert the wires. Press the connector button down and insert the wire as far as it will go. If the wire is in correctly, the button will stay down when you let it go.
    • You may need to strip the wire ends. There should be ⅓ to ½ inch of straight copper wire exposed.
  • Press the display onto the base until it clicks into place and turn your system power back on.
• Blocked air filter
• Blocked drain/drip pan tubes
• The fuse on the control board has blown

If this just started happening on a thermostat that has been working correctly and you are experiencing hot weather. Check out this link

Troubleshoot thermostat power issues during hot weather 

[jonmcwilliams]

I've seen similar issues in the past - if you have voltage on the Rc wire - it could also be that your base is not working correctly.

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[MelbaDT]

Hey folks, 

Thanks for lending a hand here, jonmcwilliams and Patrick_Caezza. 

Blondejem, chiming in to check how's your thermostat now? Have you seen the helpful responses above?

Best, 

Melba

[MelbaDT]

Hey Blondejem,

Checking back in — how's it going? Still need our help with your Nest thermostat?

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.

Best, 

Melba