Install Instructions

VR8205; VR4205 DIRECT IGNITION DUAL AUTOMATIC VALVE COMBINATION GAS CONTROLS
68-0049—03 8
Check and Adjust Gas Input and Burner Ignition
CAUTION
1. Do not exceed input rating stamped on appliance
nameplate, or manufacturer recommended burner
orifice pressure for size orifice(s) used. Make
certain primary air supply to main burner is
properly adjusted for complete combustion. Follow
appliance manufacturer 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). Convert
flow rate to Btuh as described in form 70-2602,
Gas Controls Handbook, and compare to Btuh input
rating on appliance nameplate.
3. IF CHECKING GAS INPUT WITH MANOMETER: Be
sure gas control is in OFF position before removing
outlet pressure tap plug to connect manometer
(pressure gauge). Also turn gas control knob back
to OFF 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.
STANDARD PRESSURE REGULATOR
1. Check the manifold pressure listed on the appliance
nameplate. Gas control outlet pressure should match
the nameplate.
2. With main burner operating, check gas control flow rate
using the meter clocking method or check pressure by
using a manometer connected to the outlet pressure
tap on the gas control. See Fig. 5.
3. If necessary, adjust pressure regulator to match appli-
ance rating. See Table 5 or 6 for factory set nominal
outlet pressure and adjustment setting 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 pre-
vent gas leakage.
4. If desired outlet pressure or flow rate cannot be
achieved by adjusting the gas control, check gas con-
trol inlet pressure using a manometer at the gas control
inlet pressure tap. If inlet pressure is in the nominal
range (see Table 5 or 6), replace gas control. Otherwise,
take the necessary steps to provide proper gas pres-
sure on the control.
SLOW-OPENING AND STEP-OPENING PRESSURE
REGULATORS
1. Check the full rate manifold pressure listed on the
appliance nameplate. Gas control full rate outlet pres-
sure should match this rating.
2. With main burner operating, check gas control flow rate
using the meter clocking method or pressure using a
manometer connected to the outlet pressure tap on the
gas control. See Fig. 5.
3. If necessary, adjust pressure regulator to match appli-
ance rating. See Table 5 or 6 for factory set nominal
outlet pressure and adjustment setting range.
a. Remove pressure regulator adjustment 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 pre-
vent gas leakage.
4. If desired outlet pressure or flow rate cannot be
achieved by adjusting the gas control, check gas con-
trol inlet pressure using a manometer at the gas control
inlet pressure tap. If inlet pressure is in the nominal
range (see Table 5 or 6), replace gas control. Otherwise,
take the necessary steps to provide proper gas pres-
sure to the control.
5. STEP-OPENING PRESSURE REGULATORS ONLY. Care-
fully check burner lightoff at step pressure. Make sure
burner lights smoothly and without flashback to orifice.
Make sure all ports remain lit. Cycle burner several
times, allowing at least 30 seconds between cycles for
regulator to resume step function. Repeat after allow-
ing burner to cool. Readjust full rate outlet pressure, if
necessary, to improve lightoff characteristics.
Table 5. Pressure Regulator Specification Pressures (in. wc).
Model
Type
Type
of Gas
Nominal Inlet
Pressure Range
Factory Set Nominal Outlet Pressure Setting Range
Step Full Rate Step Full Rate
Standard,
slow-opening
Natural 5.0 - 7.0 — 3.5 — 3.0 - 5.0
LP 12.0 - 14.0 — 10.0 — 8.0 - 12.0
Step-opening Natural 5.0 - 7.0 0.9 3.5 — 3.0 - 5.0
LP 12.0 - 14.0 2.2 10.0 — 8.0 -12.0
Table 6. Pressure Regulator Specification Pressures (kPa).).
Model
Type
Type
of Gas
Nominal Inlet
Pressure Range
Factory Set Nominal Outlet Pressure Setting Range
Step Full Rate Step Full Rate
Standard,
slow-opening
Natural 1.2 - 1.7 — 0.9 — 0.7 - 1.2
LP 2.9 - 3.9 — 2.5 — 2.0 - 3.0
Step-opening Natural 1.2 - 1.7 0.9 0.9 None 0.7 - 1.2
LP 2.9 - 3.9 2.2 2.5 None 2.0 - 3.0