6
TABLE 7—PRESSURE REGULATOR SPECIFICATION PRESSURES IN kPa.
OUTLET PRESSURE
NOMINAL
SETTING
TYPE
NOMINAL INLET
FACTORY SETTING
RANGE
MODEL
OF GAS
PRESSURE RANGE
Step
Full Rate
Step
Full Rate
A,M
NATURAL
1.2-1.7
—
0.9
—
0.7-1.2
LP
2.9-3.9
—
2.7
—
2-3
C,P
NATURAL
1.2-1.7
0.2
0.9
None
0.7-1.2
LP
2.9-3.9
0.5
2.7
None
2-3
CHECK SAFETY SHUTDOWN PERFORMANCE
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE IN-
JURY OR DEATH
Perform the safety shutdown test any time work is
done on a gas module.
1. Place gas control knob in PILOT position. Main burner
should go off and pilot should remain lit.
2. Extinguish pilot flame. Pilot gas flow should stop
within 2-1/2 minutes. Safety shutoff of pilot gas provides
complete shutdown since safety shutoff valve blocks flow of
gas to main burner and pilot.
3. Relight pilot burner and operate system through one
complete cycle to make sure all controls operate properly.
6. Check power unit resistance. If above 11 ohms,
replace gas control.
IF MAIN BURNER WILL NOT COME ON WITH CALL
FOR HEAT
1. Make sure gas control knob is in the ON position.
2. Adjust thermostat several degrees above room tem-
perature.
3. Disconnect leadwires to 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 valve operator.
4. Measure the open and closed thermocouple output
voltages and compare to acceptable range charts in the
thermocouple specifications or in the Gas Controls Hand-
book. Replace the thermocouple 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 control.
SERVICE
CAUTION
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 reener-
gizing step-opening model to ensure lightoff at step
pressure.
IF PILOT WILL NOT LIGHT
1. Ensure 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 4. If pilot still will not light:
a. Check pilot gas adjustment screw. If closed, read-
just pilot flame. Refer to page 4.
b. Perform gas leak test at compression fitting. If leak
is detected, replace old compression fitting or tighten new
one. Refer to page 3.
c. Ensure that pilot burner tubing or orifice is not
clogged. If clogged, replace combination gas control.
IF PILOT 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 pilot flame adjustment, refer to page 4.
3. Check the wiring between the thermocouple and the
valve operator in the gas control.
4. Ensure jumper between valve operator and power
unit is secure and connections are clean.
5. If pilot still goes out, measure the open and closed
thermocouple circuit output voltages. Compare to accept-
able range charts in the thermocouple specifications or in
the Gas Controls Handbook. Replace the thermocouple if
voltages are outside the acceptable range.
INSTRUCTIONS TO THE HOMEOWNER
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE IN-
JURY, OR DEATH
Follow these warnings exactly:
1. Pilot must be lit manually. Follow these instruc-
tions exactly.
2. Before lighting, smell around the appliance for
gas. Be sure to smell next to floor because LP gas
is heavier than air.
3. IF YOU SMELL GAS:
•
Turn off gas supply at appliance service valve.
On LP gas systems, turn off gas supply at the
tank.
•
Do not light any appliances in the house.
•
Do not touch electrical switches or use the
phone.
•
Leave the building and use a neighbor’s phone
to call your gas supplier.
•
If you can not reach your gas supplier, call the
fire department.
4. Do not force the gas control knob. 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 gas control should be re-
placed by a qualified service technician. Force or
attempted repair may result in fire or explosion.
5. The gas control must be replaced in case of any
physical damage, tampering, bent terminals, miss-
ing or broken parts, stripped threads, or evidence
of exposure to heat.