VR8215S,T DIRECT IGNITION COMBINATION GAS CONTROLS
69-2253—01
6
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 70-2602,
Gas Controls Handbook, and compare to Btuh
input rating on appliance nameplate.
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
switch 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 (S and T) 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 6 and 7 for factory-
set nominal outlet pressure and adjustment range.
a. Remove the pressure regulator adjustment cap
screw.
b. Using a screwdriver, turn the inner adjustment
screw (Fig. 6) clockwise
to increase or
counterclockwise
to decrease the gas
pressure to the burner.
c. 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 6 and
7), replace the gas control. Otherwise, take the
necessary steps to provide proper gas pressure to
the control.
Check Safety Lockout
(Slow-Opening Controls Only)
1.
With the system power off and the thermostat set to
call for heat, manually shut off the gas supply.
2.
Energize ignition control and start timing safety
lockout time. When spark ignition terminates, stop
timing.
NOTE: When using the VR8215T, the specified
ignition control safety lockout time must
exceed 8.5 seconds for the system to
function properly.
3.
After spark cutoff, manually reopen the gas control
switch. No gas should flow to the main burner.
4.
Reset the system by adjusting the thermostat below
room temperature, wait 30 seconds, and then move
the thermostat setting up to call for heat. Normal
ignition should occur.
Table 6. Pressure Regulator Specification
Pressures (in. wc).
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 before starting, and
compare to the safety shutdown or safety
lockout tests recommended for the direct ignition
(DI) module. Where different, use the procedure
recommended for the ignition module.
1.
Turn off gas supply.
2.
Set thermostat or controller above room
temperature to call for heat.
3.
Watch for ignition spark or for glow at hot surface
igniter either immediately or following prepurge.
See Direct Ignition module specifications.
4.
Time the length of spark operation. See the Direct
Ignition module specifications.
5.
After the module locks out, open the manual gas
cock and make sure no gas is flowing to the main
burner.
6.
Set the thermostat below room temperature and
wait one minute.
7.
Operate system through one complete cycle to
make sure all controls operate properly.
Model
Type
Type of
Gas
Nominal
Inlet
Pressure
Range
Factory Set
Nominal
Outlet
Pressure
Setting
Range
Standard,
Slow
NAT
5.0-7.0
3.5
2.5-3.5
LP
12.0-14.0 10.0
8.0-12.0