STARTUP AND CHECKOUT
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE IN-
JURY, OR DEATH
1. Do not force the gas control knob. Only use
you hand to push down or turn the gas control
knob. Never use any tools.
2. If the gas control knob will not operate by
hand, or if the knob stays depressed after it is
released, the control should be replaced by a
qualified service technician.
3. Perform the gas leak test described below any
time work is done on a gas system.
GAS CONTROL KNOB SETTINGS
The gas control knob has three settings:
OFF prevents pilot and main gas flow through the
control.
PILOT permits gas flow to pilot burner as long as gas
control knob is held down or generator current is above the
power unit dropout value.
ON permits gas flow into the combination gas control
body. Pilot gas is controlled as in the PILOT position. Main
burner gas is controlled by the thermostat and automatic
valve operator.
PERFORM GAS LEAK TEST
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE IN-
JURY, OR DEATH
Check for gas leaks with soap and water solution
any time work is done on a gas system.
GAS LEAK TEST:
1. Pain pipe connections upstream of gas control with
rich soap and water solution. Bubbles indicate gas leak.
2. If leak is detected, tighten pipe connections.
3. Stand clear of main burner while lighting to prevent
injury caused from hidden leaks which could cause flash-
back in the appliance vestibule. Light main burner.
4. With main burner in operation, paint pipe joints (in-
cluding adapters) and control inlet and outlet with rich soap
and water solution.
5. If another leak is detected, tighten adapter screws,
joints, and pipe connections.
6. Replace part if leak can’t be stopped.
To adjust:
1. Remove pilot adjustment cover screw. Refer to Fig. 2
or 3.
2. Turn inner adjustment screw clockwise
to de-
crease or counterclockwise
to increase pilot flame.
3. Always replace cover screw after adjustment and
tighten firmly to ensure proper operation.
LIGHT PILOT
1. Turn gas control knob clockwise
to OFF. Wait
five minutes to dissipate any unburned gas. Sniff around the
appliance near the floor. Don’t relight pilot if you smell gas.
2. Turn gas control knob counterclockwise
to
PILOT. Push down and hold the knob while you light pilot
burner.
3. Hold the gas control knob down about one minute,
then release. If the pilot goes out, turn gas control knob
clockwise
to OFF. Repeat steps 1-3.
4. Release gas control knob. If pilot remains lit, turn
counterclockwise
to ON.
ADJUST PILOT FLAME
The pilot flame should envelop 3/8 to 1/2 in. [10 to 13 mm]
of the tip of the generator. Refer to Fig. 9.
Fig. 9—Proper flame adjustment.
TURN ON MAIN BURNER
Follow instructions provided by appliance manufacturer
or turn up thermostat to call for heat.
CHECK AND ADJUST GAS INPUT TO MAIN BURNER
CAUTION
1. Do not exceed input rating stamped on appliance
nameplate, or manufacturer’s recommended
burner orifice pressure for size orifice(s) used.
Make certain primary air supply to main burner is
properly adjusted for complete combustion. Fol-
low appliance manufacturer’s instructions.
2. IF CHECKING GAS INPUT BY CLOCKING GAS
METER: Make certain there is no gas flow through
the meter other than to the appliance being
checked. Other appliances must remain off with
their pilots extinguished (or their consumption
must be deducted from the meter reading). Con-
vert flow rate to Btuh as described in form 70-
2602, Gas Controls Handbook, and compare to
the Btuh input rating on appliance nameplate.
3. IF CHECKING GAS INPUT WITH MANOME-
TER: Make certain gas control is in PILOT posi-
tion before removing outlet pressure tap plug to
connect manometer (pressure gauge). Also turn
gas control knob back to PILOT when removing
gauge and replacing plug. Before removing inlet
pressure tap plug, shut off gas supply at the
manual valve in the gas piping to the appliance
or, for LP, at the tank. Also shut off gas supply
before disconnecting manometer and replacing
plug. Repeat Gas Leak Test at plug with main
burner operating.
VS820A,V; VS821A (Standard Pressure Regulator)
1. Check the manifold rating listed on the appliance
nameplate. Gas control outlet pressure should match the
nameplate.
2. With main burner operating, check gas control outlet
gas flow using the meter clocking method or pressure
using a manometer connected to the outlet pressure tap
on the gas control. Refer to Fig. 2 or 3.
3. If necessary, adjust pressure regulator to match ap-
pliance rating. Refer to Table 5 for factory set nominal
outlet pressure and adjustment range.
a. Remove pressure regulator adjustment cap
screw.
b. Using screwdriver, turn inner adjustment screw
clockwise
to increase or counterclockwise
to decrease gas pressure to burner.
c. Always replace cap screw and tighten firmly to
ensure system functions properly.
4. If desired outlet pressure or flow rate cannot be
4
M18972
PROPER FLAME
ADJUSTMENT
3/8 TO 1/2 IN.
(10 TO 13 MM)
GENERATOR
Summary of Contents for VS820A
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