VR8105, VR8205, AND VR8305 DIRECT IGNITION COMBINATION GAS CONTROLS
Check and Adjust Gas Input and Burner Ignition
IMPORTANT
1.Do not exceed input rating stamped on appliance nameplate, or manufacturer’s 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 the pilots extinguished (or deduct their consumption from the meter reading). Convert flow rate to Btuh as described in form
3.IF CHECKING GAS INPUT WITH MANOMETER: Make sure the gas control is in the OFF position before removing outlet pressure tap plug to connect manometer (pressure gauge). Also move the gas control knob back to the OFF position when removing the gauge and replacing the 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.
NOTE: Check the inlet pressure before adjusting the pressure regulator.
Standard and Slow-Opening (H, K and M) Models
1.Carefully check the main burner lightoff. Make sure that the main burner lights smoothly and that all ports remain lit.
2.Check the full rate manifold pressure listed on the appliance nameplate. Gas control full rate outlet pressure should match this rating.
3.With main burner operating, check the control flow rate using the meter clocking method or check pressure using a manometer connected to the outlet pressure tap on the control. See Fig. 6.
4.If necessary, adjust the pressure regulator to match the appliance rating. See Tables 8 and 9 for
a. Remove the pressure regulator adjustment cap
screw.
Using a screwdriver, turn the inner adjustment screw
(Fig. 6) clockwise 
to increase or
counterclockwise 
to decrease the gas pressure to the burner.
b.Always replace the cap screw and tighten firmly to prevent gas leakage.
5.If the desired outlet pressure or flow rate cannot be achieved by adjusting the gas control, check the gas control inlet pressure using a manometer at the inlet pressure tap of the gas control. If the inlet pressure is in the nominal range (see Tables 8 and 9), replace the gas control. Otherwise, take the necessary steps to provide proper gas pressure to the control.
NOTE: If the burner firing rate is above 150,000 Btuh on VR8305 models (see Table 1 for VR8305 capacities), it may not be possible to deliver the desired outlet pressure. This is an application issue, not a control failure. Take whatever steps are required to correct the situation.
Step-Opening (P) Models
1.Carefully check the main burner lightoff. Make sure that the main burner lights smoothly and that all ports remain lit.
2.Check the full rate manifold pressure listed on the appliance nameplate. Gas control full rate outlet pressure should match this rating.
3.With main burner operating, check the gas control flow rate using the meter clocking method or check pressure using a manometer connected to the outlet pressure tap on the gas control. See Fig. 6.
4.If necessary, adjust the pressure regulator to match the appliance rating. See Tables 8 and 9 for
a. Remove the pressure regulator adjustment cap
screw.
Using a screwdriver, turn the inner adjustment screw
(Fig. 6) clockwise | to increase or |
counterclockwise | to decrease the gas pressure |
to the burner. |
|
b.Always replace the cap screw and tighten firmly to prevent gas leakage.
5.If the desired outlet pressure or flow rate cannot be achieved by adjusting the gas control, check the gas control inlet pressure using a manometer at the inlet pressure tap of the control. If the inlet pressure is in the nominal range (see Tables 8 and 9), replace the control. Otherwise, take the necessary steps to provide proper gas pressure to the control.
6.Carefully check the burner lightoff at step pressure. Make sure the burner lights smoothly and without flashback to the orifice. Make sure all ports remain lit. Cycle the burner several times, allowing at least 60 seconds between cycles for the regulator to resume the step function. Repeat after allowing the burner to cool. Readjust the full rate outlet pressure, if necessary, to improve lightoff characteristics.
Two-Stage (Q) Models
1.Set appliance to operate on high.
2.Carefully check the main burner lightoff. Make sure that the main burner lights smoothly and that all ports remain lit.
3.Check the full rate (high) manifold pressure listed on the appliance nameplate for high pressure. The gas control full rate outlet pressure should match this rating.
8 |
