69-0668—1
9
VR8300A CONTINUOUS PILOT COMBINATION GAS CONTROL
SERVICE
WARNING
Fire or Explosion Hazard.
Can cause property damage, severe injury or
death
Do not disassemble the gas control; it contains no
replaceable components. Attempted disassembly
or repair can damage the gas control.
CAUTION
Hazardous voltage.
Improper installation can burn out thermostat
heat anticipator.
Do not apply a jumper across or short the valve
coil terminals.
IMPORTANT

Allow 60 seconds after shutdown before re-

energizing step-opening model to ensure lightoff

at step pressure.

If Pilot Burner Flame does not Light:

1. Make sure that the main gas supply valve is open
and the pilot gas supply line is purged of air.
2. Light the pilot burner flame following procedures in
Light the Pilot Burner Flame section. If pilot burner
flame does not light:
a. Check the pilot gas adjustment screw. If
closed, readjust the pilot flame. Refer to
Adjust the Pilot Burner Flame section.
b. Perform the Gas Leak Test at the compres-
sion fitting. If a gas leak is detected, replace
the old compression fitting or tighten the newly
installed one. See Fig. 5.
c. Make sure that the pilot burner tubing or pilot
burner orifice is not clogged.

If Pilot Burner Flame Goes Out when Gas

Control Knob is Released:

1. Make sure the gas control knob is held in at least
one minute to allow the thermocouple time to heat.
2. Check the pilot burner flame adjustment. Refer to
Adjust the Pilot Burner Flame section.
3. Check the wiring between the thermocouple and the
gas control valve operator.
4. Make sure that the thermocouple connection to the
power unit is tightened 1/4 turn beyond finger tight.
5. If pilot burner flame goes out, measure the open and
closed thermocouple output voltage. Compare it to
the acceptable range charts in the thermocouple
specifications or in the Gas Controls Handbook.
Replace the thermocouple if voltages are outside
the acceptable range.
6. Check the power unit resistance. If it is above 11
ohms, replace the gas control.

If Main Burner does not Come on with Call

For Heat:

1. Make sure the gas control knob is in the ON
position.
2. Adjust the thermostat several degrees above the
room temperature.
3. Use an ac voltmeter to measure the 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 gas pressure is correct,
replace the gas control.
4. Measure the open and closed thermocouple output
voltages and compare to the acceptable range
charts in the thermocouple specifications or in the
Gas Controls Handbook. Replace the thermocouple
if voltages are outside the acceptable range.

If Main Burner is Overfiring:

Adjust the gas control pressure regulator to the correct
pressure. If the regulator cannot be adjusted and supply
pressure is in the normal range, replace the gas control.

Instructions to the Homeowner

WARNING
Fire or Explosion Hazard.
Can cause property damage, severe injury,
or death.
Follow these warnings exactly:
1. Pilot burner flame must be lit manually. Follow
these instructions exactly.
2. Before lighting pilot burner flame, smell
around the appliance area for gas. Be sure to
smell next to floor because LP gas is heavier
than air.
3. IF YOU SMELL GAS:
• Immediately turn off the gas supply at the
appliance service valve. On LP gas
systems, turn off the gas supply at the gas
tank.
• Do not light any appliances in the house.
• Do not touch electrical switches or use the
phone.
• Leave the building and call your gas
supplier.
• If you can not reach your gas supplier, call
the fire department.
4. Do not force the gas control knob on the
appliance. Use only your hand to turn the gas
control knob. Never use any tools. If the gas
control knob does not operate by hand, have
a qualified service technician replace the
control. Force or attempted repair can result in
a fire or explosion.
5. The gas control is a safety device, it must be
replaced in case of any physical damage such
as bent terminals, missing or broken parts,
stripped threads, or evidence of exposure to
heat.