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24

Error 24 — Compressor failed to start

Lennox · EL18KSLV Series Outdoor Units

What does 24 mean?

The compressor did not start when a call for operation occurred. This requires a check of the compressor's starting ability.

Common Causes

  • Compressor fault
  • Wiring issue to the compressor
  • Control board issue

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Refer to the compressor testing procedure in the manual.

  2. 2

    Check all electrical connections to the compressor.

  3. 3

    Ensure the control board is commanding the compressor to start.

Browse all codes in this manual (43)
Verified technical data. Last updated: April 2026

Related Faults

1Error 1 — EEPROM malfunction or damage10Error 10 — Outdoor defrost sensor failure11Error 11 — Suction temperature sensor failure
Source: Lennox EL18KSLV Series Outdoor Units
Open Manual (Page 70)Search more codes in this manual