Lennox

6 flash

Lockout

PS lockout

Hardened 3-flash / 2-flash. Retries used up on draft.

3 plates — walk the one on the cabinet

First check

1 Prove inducer and the live code

Do not pull power — that clears the Lennox ML180 active code. Write 6 flash. Is the inducer spinning on this call? Silent inducer is not a pressure switch. Fix chimney / inducer / common vent, then reset.

Expect: 120 VAC at the inducer on a heat call. Wheel turning.

If fail: 120 VAC missing → IFC / door switch / incoming power. Voltage + dead motor → inducer.

If pass: Inducer running + this code → trap, hose, switch, vent (step 2).

The rest of the walkthrough is Diagnose.

On the plates

Fix the 3-flash physics (trap/PVC) before you reset.
Fix chimney / inducer / common vent, then reset.

Plates that use 6 flash

ML180
Merit · 80% · metal vent · LED flash
Hardened 3-flash.
Diagnose ML180 — Sign in
ML193
Merit · 93% or 80% CT · LED flash
Diagnose ML193 — Sign in
ML196
Merit · single- or two-stage · LED flash · 96%
Diagnose ML196 — Sign in

Same number, other makers

6 flash on Lennox is not the same code on these plates.