68-0150
8
VR8405
STARTUP AND CHECKOUT
TURN ON GAS CONTROL
Rotate the gas control knobs counterclockwise
to
ON.
TURN ON MAIN BURNER
Follow instructions provided by appliance manufacturer
or turn up thermostat to call for heat.
CHECK GAS INPUT TO MAIN BURNER
CAUTION
1. Do not exceed the input rating stamped on the
appliance nameplate, or manufacturer recom-
mended burner orifice pressure for the size
orifice(s) used. Make certain the primary air
supply to the main burner is properly adjusted
for complete combustion (refer to the appli-
ance manufacturer instructions).
2. WHEN CHECKING GAS INPUT BY
CLOCKING THE GAS METER:
• Make sure that the only gas flow through
the meter is that of the appliance being
checked.
• Make certain that other appliances are turned
off with pilot burners extinguished (or de-
duct that gas consumption from the meter
reading).
• Convert flow rate to Btuh as described in
the Gas Controls Handbook, form 70-2602,
and compare to the Btuh input rating on
the appliance nameplate.
Standard-Opening and Slow-Opening Pressure
Regulator
1. The gas control outlet pressure should match the
manifold pressure listed on the appliance nameplate.
2. With the main burner operating, check the gas con-
trol flow rate using the meter clocking method.
3. If the desired gas flow rate is not as stamped on the
control, check the gas control inlet pressure using a ma-
nometer at the inlet pressure tap. Regulators are fixed. They
are not adjustable. If the inlet pressure is in the normal
range (refer to Table 4), replace the entire gas control.
Otherwise, take the necessary steps to provide proper gas
pressure to the gas control.
NOTE: Factory set outlet pressure is not field adjustable.
Step-Opening Pressure Regulator
1. The gas control outlet pressure should match the
manifold pressure listed on the appliance nameplate.
2. With the main burner operating, check the gas con-
trol flow rate using the meter clocking method.
3. If desired flow rate is not as stamped on the control,
check the inlet pressure using a manometer at inlet pres-
sure tap or upstream of the gas control. Regulators are
fixed. They are not adjustable. If the inlet pressure is in the
normal range (refer to Table 4), replace the entire gas con-
trol. Otherwise, take the necessary steps to provide proper
gas pressure to the gas control.
4. Carefully check main burner lightoff at the step
pressure. Make sure the main burner lights smoothly and
without flashback to the orifice and that all ports remain
lit. Cycle the main burner several times, allowing at least
30 seconds between cycles for the regulator to resume the
step function. Repeat after allowing main burner to cool.
CHECK SAFETY SHUTDOWN PERFORMANCE
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY, OR DEATH.
Perform the safety shutdown test any time work is
done on a gas system.
NOTE: Read steps 1 through 7 below before starting, and
compare to the safety shutdown or safety lockout tests
recommended for the direct ignition (DI) module. Where
they differ, use the procedure recommended for the
module.
NOTE: Factory set outlet pressure is not field adjustable.
Factory Set Outlet Pressure
Model
Type of Gas
Nominal Inlet Pressure
Step
Full Rate
H (Slow-opening)
Natural
7.0 [1.7]
—
3.0 - 5.0 [0.7 - 1.2]
LP
14.0 [3.9]
—
8.0 - 12.0 [2.0 - 3.0]
M (Standard)
Natural
7.0 [1.7]
—
3.0 - 5.0 [0.7 - 1.2]
LP
14.0 [3.9]
—
8.0 - 12.0 [2.0 - 3.0]
P (Step-opening)
Natural
7.0 [1.7]
0.7, 0.9, 1.2, 1.7,
[0.17, 0.22, 0.30, 0.42]
3.0 - 5.0 [0.7 - 1.2]
LP
14.0 [3.9]
1.4, 2.5, 4.0, 5.5
[0.35, 0.62, 1.0, 1.4]
8.0 - 12.0 [2.0 - 3.0]
TABLE 4—PRESSURE REGULATOR SPECIFICATION PRESSURES IN IN. WC [kPa].