Vanguard VMH26TN Owner's Operation And Installation Manual page 26

TROUBLE-
SHOOTING
Continued
26
OBSERVED
PROBLEM
Burner does not light
after ODS/pilot is lit
Delayed ignition of
burner
Burner backfiring
during combustion
Yellow flame during
burner combustion
Slight smoke or odor
during initial operation
Fireplace produces a
whistling noise when
burner is lit
POSSIBLE
CAUSE
1. Burner orifice is
clogged
2. Burner orifice diameter
is too small
3. Inlet gas pressure is
too low
1. Manifold pressure is
too low
2. Burner orifice is
clogged
1. Burner orifice is
clogged or damaged
2. Burner damaged
3. Low inlet gas pressure
4. Gas regulator defective
1. Not enough air
2. Gas regulator defective
1. Residues from manu-
facturing processes
1. Turning control knob
to HI position when
burner is cold
2. Air in gas line
3. Air passageways on
fireplace blocked
4. Dirty or partially
clogged burner orifice
REMEDY
1. Clean burner (see
Cleaning and Mainte-
nance, page 24) or
replace burner orifice
2. Replace burner orifice
3. Contact local natural gas
company
1. Contact local natural gas
company
2. Clean burner (see
Cleaning and Mainte-
nance, page 24) or
replace burner orifice
1. Clean burner (see
Cleaning and Mainte-
nance, page 24) or
replace burner orifice
2. Replace burner pressure
3. Contact local natural gas
company
4. Replace gas regulator
1. Check burner for dirt
and debris. If found,
clean burner (see
Cleaning and Mainte-
nance, page 24)
2. Replace gas regulator
1. Problem will stop after a
few hours of operation
1. Turn control knob to LO
position and let warm up
for a minute
2. Operate burner until air
is removed from line.
Have gas line checked
by local natural gas
company
3. Observe minimum
installation clearances
(see Figure 6 and 7,
page 11)
4. Clean burner (see
Cleaning and Mainte-
nance, page 24) or
replace burner orifice
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