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Not running / fault code

What is going on

Possible causes and checks for: not running / fault code.

Likely causes

  • No 120 V to motor
  • No low-voltage communication from system board
  • Burnt/loose/frayed harness
  • Failed control module

Check in this order

  1. In that order, then follow the manufacturer's code chart
  2. Replace module (not repairable)

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Source: General HVAC service practice — verify per model. Written in our own words; check the manual for your exact model.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.