FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY, OR DEATH
,
Do not apply jumper across (or short) valve coil
terminals, even temporarily. Doing so may burn out
heat anticipator in thermostat.
IMPORTANT
Allow 60 seconds after shutdown before
step-opening model to ensure
at step
pressure.
IF PILOT WILL NOT LIGHT
1. Make sure the main gas supply valve is open and the
pilot gas supply line is purged of air.
2. Attempt to light pilot following procedure in “Light
Pilot”. page 9. If pilot still will not light:
a. Check pilot gas adjustment screw. If closed,
readjust pilot flame. Refer to page 9.
b. Perform gas leak test at compression fitting. If
leak is detected, replace old compression fitting or
tighten new one. Refer to page 7.
c. Ensure that pilot burner tubing or orifice is not
clogged. If clogged, replace combination gas con-
trol.
IF PILOT GOES OUT WHEN GAS CONTROL KNOB IS
RELEASED
1. Make sure the gas control knob is held in at least one
minute
therm
heat.
2. Adjust thermostat several degrees above room
temperature.
3. For
and VS821, disconnect
lower
left TH terminal and lower right PP terminal to isolate valve
operator coil from balance of circuit. Measure resistance of
coil. If coil is not 2 ohms 10 percent, replace VS824A
Valve Operator.
4.
Powerpile applications, ensure jumper between
valve operator and power unit is secure and connections
are clean.
5. In thermocouple applications, ensure connection to
power unit is tightened 1/4 turn beyond finger tight.
6. If pilot still goes out, measure the open and closed
thermocouple or generator circuit output voltages. Com-
pare to acceptable range charts in the thermocouple or
generator specifications or in the Gas Controls Handbook.
Replace the thermocouple or generator if voltages are
outside the acceptable range.
7. Check power unit resistance. If above 11 ohms,
replace gas control,
IF MAIN BURNER WILL NOT COME WITH CALL FOR
HEAT
1. Make sure gas control knob is in the ON position.
2. Adjust thermostat several degrees above room
temperature.
3. For VS820 and VS821, disconnect
lower
left TH terminal and lower right PP terminal to isolate valve
operator coil from balance of circuit. Measure resistance of
coil. If coil is not 2 ohms 10 percent, replace VS824A
Valve Operator.
4. For all other models, use an
measure
voltage across terminals TH and TR. If:
a. No voltage is present, check the control circuit for
proper operation.
b. 24 Vac is present, but first operator did not “click”
open, check for excessive inlet gas pressure. If inlet
pressure is correct, replace the control.
c. 24 Vac is present and first valve operator
“clicked” open, replace second operator assembly.
5. Measure the open and closed thermocouple or gen-
erator output voltages and compare to acceptable range
charts in
specifications or in
the Gas Controls Handbook. Replace the thermocouple or
generator if voltages are outside the acceptable range.
IF BURNER IS OVERFIRING
Adjust pressure regulator to correct pressure. If regula-
tor cannot be adjusted and supply pressure is in normal
range, replace complete gas
INSTRUCTIONS TO THE HOMEOWNER
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY, OR DEATH
Follow these warnings and lighting instructions
exact
1. Before lighting, smell all around the appli-
ance area for gas. If appliance uses LP
(bottled) gas, also be sure to smell next to
floor because LP gas is heavier than air. If you
smell gas, immediately shut off the manual
valve
SYSTEMS, AT THE TANK. Do not try to light
any appliances in the house. Do not touch
electrical switches or use the phone. LEAVE
THE BUILDING and call your gas supplier
from a neighbor’s house. If your gas supplier
cannot be reached, call the fire department.
2. Do not force the gas control knob on the ap-
pliance. Use only your hand to push down or
turn the gas control knob. Never use any
tools. If the gas control knob will not operate
by hand, the control should be replaced by a
qualified service technician. Force or at-
tempted repair may result in fire or explosion.
3. The control must be replaced if it has been
flooded with water.
4. The control is a SAFETY DEVICE. It must be
replaced in case of any physical damage,
tampering, bent terminals, missing or broken
parts, stripped threads, or evidence of expo-
sure to heat.
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