Dometic 1 flash fault code — Furnace
Applies to: Hydro Flame AFM Series Furnaces AFMD16/AFMD20/AFMD25/AFMD30/AFMD35
What 1 flash means
The Dometic Hydro Flame AFM technical installation manual lists 1 flash with a 3-second pause as limit switch or airflow problems.
Owner-safe checks
- Turn the furnace off.
- Check that interior registers and exterior intake/exhaust openings are unobstructed.
- Do not restart if vents were covered, soot is present, or the furnace smells unusual.
Service-only work
- Limit-switch, airflow switch, burner, board, or combustion diagnosis is qualified RV furnace service work.
Safety boundary
RV furnaces burn LP gas and can create fire, explosion, electrical, burn, and carbon monoxide hazards. Shut the furnace off and do not service burner, board, wiring, gas, or combustion parts unless qualified.