Lennox E270 & E271 — Soft lockout, ignition retries exceeded

What this error means

The E-code versions of Watchguard: E270 = maximum ignition retries with no flame current sensed (dirty flame sensor territory), E271 = retries exhausted with the last failure caused by the pressure switch opening (venting/inducer territory). Both are soft lockouts that auto-retry.

Symptoms

• Repeated failed ignitions then silence
• E270 or E271 displayed
• Heat returns after ~an hour, then fails again

Try this first (safe DIY steps)

1. E270: clean the flame sensor (universal guide) — the dominant cause
2. E271: check vent/intake terminations and condensate drain
3. Power off 30 seconds to clear immediately; fix the cause or it returns

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

When to call a technician

If cleaning/clearing doesn't hold: standard ignition-system or pressure-switch diagnosis ($80–$400).