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426

Alert Code 426 — Excessive Inverter Alarms

Lennox · Communicating Systems

What does 426 mean?

This critical alert occurs after 10 inverter alarms within 60 consecutive minutes, causing the control to lock out. The inverter will flash codes 12 to 14 and 53.

Common Causes

  • Repeated inverter alarm events

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Disconnect power to the outdoor control.

  2. 2

    Wait for 30 seconds.

  3. 3

    Reconnect power to the outdoor control to restart the system.

Browse all codes in this manual (41)
Verified technical data. Last updated: April 2026

Related Faults

14Inverter Flash Code 14 (Red 1 flash, Green 4 flashes) — OD Inverter Compressor Slowdown21Inverter Flash Code 21 (Red 2 flashes, Green 1 flash) — OD Inverter DC Peak Fault262 red flashes, 6 green flashes — Compressor startup fail
Source: Lennox Communicating Systems
Open Manual (Page 56)Search more codes in this manual