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Step 1. With main burner in operation, remove outer jacket door remove inner door as described in this manual,
see inner door removal, inspection and replacement section (page 35).
Step 2. To adjust for proper burning, loosen the air shutter nut, rotate the air shutter to close the opening in the
burner, then slowly rotate the air shutter open until flame becomes as blue as possible with a minimum of
yellow tips. Tighten the air shutter nut.
Too much air will cause the flame to lift off the burner ports and create noisy burner operation.
Too little air will result in soot formation.
Step 3. Replace inner door as described in this manual, observe burner operation. Burner should operate as
adjusted in step 2. If not, repeat air shutter adjustment compensating for proper burner operation with inner
At periodic intervals (every 6 months) a visual inspection should be made of the pilot and main burner for proper
operation and to assure no debris is accumulating.
Pilot flame should be stable, some causes for an unstable pilot flame are:
a) Water heater vent is less than the allowable vent length.
b) Gas pressure is out of specification.
c) Pilot flame not fully engulfing spark/flame sensor.
d) Door was not sealed properly after servicing.
Main burner should light smoothly from pilot and burn with a blue flame with a minimum of yellow tips.
Steel burner models self adjust air to gas ratio mixture and do not have an adjustable air shutter. Cast iron burner can
have the gas and air mixture properly proportioned by adjusting the air shutter on the mixer face of the main burner
(see cast iron burner adjustment below).
Main burner must be free from any debris accumulation that may effect burner operation (see burner cleaning
procedure on page 14).
Burner Inspection and Air Shutter Adjustment.
Cast Iron Burner Air Shutter Adjustment
Inner door and burner components may be HOT when performing this operation. Take
necessary precaution to prevent personal injury.
Air Shutter Nut
PDX SERVICE PROCEDURE I
Burner Operation Inspection,
Adjustment, Cleaning and Replacement