System Diagnosis
Ignition failure (burner failed after retries). The furnace may lock out for safety, blowing only cold air.
Troubleshooting guide for the American Standard Furnaces system fault 2 Flashes.
A repeatable stop in the heating sequence at the same safety or prove step.
Weak grounding, marginal flame signal, or venting issues can produce inconsistent code behavior.
ACLogics walks you through American Standard Furnaces diagnostics step-by-step — so you confirm the cause before swapping parts.