HVAC Code Lookup

Goodman Furnace Code 1

Soft lockoutShown as: 1 flash, then a pause, repeating

Ignition lockout. The furnace tried to light three times, could not prove a flame, and shut itself down. The control will try again on its own about an hour later.

Manual wording: “Furnace lockout due to an excessive number of ignition "retries" (3 total)”

Documented for: Goodman GMS8, GMH8, GDS8, GDH8, GHS8, GME8, GMES80, GCES80, GMSS92, GMSS96, GCSS96 (single red diagnostic LED)

Likely causes, most common first

  1. Failure to establish flame - no gas to the burners
  2. Bad igniter or igniter alignment
  3. Improper orifices
  4. Coated, oxidized or improperly connected flame sensor
  5. Loss of flame after establishment from interrupted gas supply
  6. Lazy burner flames from improper gas pressure or a restriction in the flue
  7. Improper induced draft blower performance

What you can safely check yourself

  • Make sure the gas is on - check that another gas appliance in the house (range, water heater) still works
  • Check that the furnace door panel is fully seated so the door switch closes
  • Set the thermostat to Heat and a few degrees above room temperature
  • Turn the furnace off at its power switch for about 30 seconds, then back on, to let it try one more time

When to call a technician

If the furnace locks out again after one reset, stop. Igniter, flame sensor, gas pressure and induced draft blower diagnosis are all technician work on a live gas appliance.

A Goodman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Goodman codes