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648PRO Lights Flicker


  • Why do the lights in a 648PRO sometimes go out and come back on?
  • Clicking noise from a 648PRO with the lights turning off and on
  • Does the 648PRO run a self-test by itself?
  • Blinking or flickering lights in a 648PRO
  • Relays clicking or clicking noise
  • 648PRO turns on by itself


The 648PRO model has a self-test capability programmed into the control board. This can be initiated by a service technician through the diagnostic menu, or the unit itself runs the self-test periodically without prompting. This is a normal operation of the controls.

  • During the self-test, the control board tests the functions of the board and relays.
  • The lights turn off and on, as will other components such as the fans and compressors.
  • Clicking noises are audible from the relays on the board closing and opening.
  • The self-test takes a couple minutes and then goes back to operating normally and can happen a few times a week or even about once a day.

If the lights flicker or unit appears to turn on by itself, customer troubleshooting is not available. Contact Factory Certified Service to schedule an appointment for repair.


Need further assistance? Contact Customer Care at 800.222.7820 or provide your information below and request a Customer Care representative contact you.

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