Error Code 1 Flash
High

Amana AMSS920803BN Error Code 1 Flash: System Lockout

TL;DR
One flash on your Amana AMSS920803BN means the furnace locked out after three failed ignition attempts. On this model it most often traces to a fouled flame sensor or a failing igniter, and the board auto-resets after about one hour.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code 1 Flash Mean?

A single flash on the Amana AMSS920803BN reports a system lockout after the control module counted three failed ignition attempts (retries). The lockout is a safety feature: rather than keep opening the gas valve when a flame will not establish or hold, the Integrated Control Module stops trying for about an hour.

Because this is a single-stage furnace, the ignition sequence is straightforward — the inducer starts, the pressure switch proves draft, the hot surface igniter glows, the gas valve opens, and the flame sensor must confirm a flame through a small microamp current. If flame is not proven during the trial for ignition, or if it is lost right after, the board logs a retry. Three retries trigger the one-flash lockout.

This code sits at the end of a chain of related indications on the same board. Seven flashes (code-7, low flame signal) is the early-warning stage of the same flame-sense degradation that eventually produces a one-flash lockout, and eight flashes (code-8, igniter circuit fault) is the board detecting an igniter problem outright. On this model the fault is classified for professional service because the underlying causes — a fouled or misconnected flame sensor, a bad or misaligned igniter, no gas to the burners, or interrupted gas causing flame loss — require testing to tell apart safely.

What You'll Notice

Common Causes

Cause Likelihood DIY?
Dirty or oxidized flame sensor Most common ✗ Call a pro →
Failed or misaligned igniter Common ✗ Call a pro →
No gas supply to burners Common ✗ Call a pro →
Interrupted gas supply causing flame loss Common ✗ Call a pro →

How This Is Diagnosed

A technician isolates the cause in ignition-sequence order. They first confirm the gas is on and supply pressure is adequate, then watch a full ignition attempt to see whether the igniter glows and whether a flame establishes. If flame is proven but then drops out, attention shifts to gas pressure, the front-cover pressure switch, and the venting. The flame-sensor microamp signal is measured; a fouled rod is cleaned and re-tested, and a weak or cracked igniter is replaced. Because a poor unit or burner ground mimics a weak flame signal, grounding and the flame-sense wiring are verified as part of the check.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

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Frequently Asked Questions

Can I just clean the flame sensor myself to fix code 1 on this furnace?

On this model the code is classified as professional because the same lockout can come from gas-supply, igniter, or pressure-switch faults that need testing to tell apart. A technician will clean or replace the sensor and confirm the real cause rather than guessing.

Will the furnace reset on its own?

Yes. The Integrated Control Module automatically clears the lockout after about one hour, or sooner if you cut power at the furnace switch or breaker for 30 seconds. But if the underlying problem remains, it will simply lock out again.

Is code 1 dangerous?

The lockout itself is protective — it stops the furnace from repeatedly releasing unburned gas after failed ignition. The real risk is ignoring a repeat lockout, so have it diagnosed if it keeps coming back.

Sources

  1. Service Instructions - GMSS9*/GCSS9*/AMSS9*/ACSS9* Single Stage Gas Furnaces and Accessories
  2. Installation Instructions for *MSS9* & *CSS9* Single-Stage Gas Furnace

✓ Verified against manufacturer service manual — March 2026