Lennox E200 — Rollout circuit open (hard lockout)

What this error means

The flame rollout switch tripped or its circuit is open — flames escaped the burner enclosure at some point. This is a hard lockout and a combustion safety event: Lennox's service literature says correct the cause or replace the switch, and the cause is what matters (blocked heat exchanger, venting failure, burner problems).

Symptoms

• E200 on the 7-segment board display or iComfort thermostat alert
• Furnace locked out, won't retry

Try this first (safe DIY steps)

1. Don't repeatedly reset this one — a rollout event means combustion gases went somewhere they shouldn't
2. Power down the furnace and book a combustion inspection

Safety: power off before any physical intervention. Never bypass covers or interlocks — fuser areas run hot enough to burn.

When to call a technician

Immediately — rollout events warrant a professional inspection of the heat exchanger and venting before the furnace runs again.