Viking VGR30 Service Manual page 34

TROUBLE SHOOTING GUIDE
PROBLEM
18.Flashback-The air/gas mixture
burn near the orifice, creating
a roaring noise like a blow
torch.
19. Extinction pop-A small
explosion of gas in the
burner head occurs when
the burner is shut off.
Normal Hard Flames
Check the gas supply and set the regulator to the proper supply of gas. A properly adjusted burner should be stable
A. VGRC / VGSC I / R broiler construction prior
to Feb. 1995 used one (1) screen support. The
support was mounted internally from the
venturi forward to the front of the broiler
burner box. The screen support partially
covered the glow coil ignitor. This usually
caused slow or delayed ignition, especially
when used LP gas.
PROBABLE CAUSE
18A.Under rated burner
ignites inside the burner to
18B.Increase primary air.
18C.Flashback occurs with the
Burner valve in on off position, 18D.
the valve is probably leaking.
19A.Similar to flashback.
Blowing (lifting) Flames
Yellow Tipping
34
CORRECTION
18A. Check orifice size. Increase size if
Necessary or increase gas pressure
18B.Adjust air shutter to reduce
primary air.
18C. Change burner valve.
If #1,2 &3 corrections fail to
eliminate flash back, replace the
burner.
19A. Reduce primary air supplied to
the burner. CAUTION: do not
allow yellow tipping during
burner operation.
19B. Check orifice size.
19C. Check gas pressure.
Yellow Flames
and quiet. The flame should have a sharp, well
defined blue inner cone, no yellow tipping. The
flame should also be stable and uniform with no
flames lifting off the burner ports.
B. A change in the manufacturing of the I / R
Broiler repositioned the screen supports. The
screen supports, now two (2), are positioned
from, right to left. The glow coil ignitor is
now completely open for igniting the gas
almost immediately.
C. The first generation, VGR / VCM, screen
support should be welded in four (4) places.