The burner fires, but the flame sputters and eventually goes out.

The sputtering effect is due to air in the fuel system. When the burner chamber is hot, this sputtering effect can cause the heater to backfire. Sputtering is commonly caused by leaks in the fuel line, a damaged O-ring in the fuel nozzle, or a damaged distributor in the fuel nozzle. The most common problem is damage to the fuel nozzle.

  1. Service the fuel nozzle and inspect the O-ring and the distributor/stem in the fuel nozzle for damage. If the O-ring is damaged, replace it. If the distributor and/or stem are damaged, replace the entire nozzle.
  2. CAUTION: Make sure the burner box cover is secured to the burner box before attempting to start the heater. If the heater were to attempt to fire with the burner box cover off, it could project open flame towards the user.
  3. Once the fuel nozzle has been repaired/replaced/cleaned, press the power button on the front panel of the heater and attempt to run the heater.