VS8421 VENTFREE MILLIVOLT GAS VALVE
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Perform Gas Leak Test
WARNING
Fire or Explosion Hazard.
Can cause property damage, severe injury or
death.
Stand away from the main burner while lighting.
Hidden gas leaks can cause flashbacks in the
appliance vestibule. Check for gas leaks with rich
soap and water solution any time work is done on
a gas system.
Gas Leak Test
1.
Paint the pipe connections upstream of the gas
valve with a rich soap and water solution. Bubbles
indicate a gas leak.
2.
If a leak is detected, tighten the pipe connections.
3.
Light the main burner.
4.
With the main burner in operation, paint the pipe
joints (including adapters) and valve inlet and
outlet with a rich soap and water solution.
5.
If another leak is detected, tighten the adapter
screws, joints, and pipe connections.
6.
Replace the part if the leak cannot be stopped.
Turn on System
Rotate the gas control knob counterclockwise
to
ON.
Turn on Main Burner
Follow the instructions provided by the appliance
manufacturer or turn up the thermostat to call for heat.
Check and Adjust Gas Input
and Burner Ignition
IMPORTANT
Do not exceed the input rating stamped on the
appliance nameplate, or the manufacturer
recommended burner orifice pressure for size
orifice(s) used.
IMPORTANT
For complete combustion, be sure the primary
air supply to the main burner is adjusted
properly. Follow the instructions of the appliance
manufacturer.
Checking Gas Input By
Clocking Gas Meter
1.
Be sure there is no gas flow through the meter
except to the appliance being checked.
NOTE:
Other appliances must remain off with the pilots
extinguished, or the consumption must be
deducted from the meter reading.
2.
Convert the flow rate to Btuh as described in the
Gas Controls Handbook, form 70-2602.
3.
Compare to the Btuh input rating on the appliance
nameplate.
Checking Gas Input With Manometer
NOTE:
Both the inlet and outlet pressure taps have a
captive screw.
1.
Be sure the gas control knob is in the OFF position.
2.
Loosen, but do not remove the outlet tap captive
screw.
3.
Attach a plastic tube with a 1/4 in. shell ID and con-
nect the manometer.
4.
Check the outlet tap pressure.
5.
Turn the gas control knob to the OFF position.
6.
Shut off the gas supply at the manual valve in the
gas piping to the appliance or, for LP, at the tank.
7.
Loosen, but do not remove the inlet tap captive
screw.
8.
Attach a plastic tube with a 1/4 in. shell ID and
connect the manometer.
9.
Check the inlet tap pressure.
10.
Turn the gas control knob to the OFF position.
11.
Repeat the Gas Leak Test at the pressure tap with
the main burner operating.
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.
1.
Place gas control knob in PILOT position. Main
burner should go off and pilot should remain lit.
2.
Extinguish pilot flame. The VS8421 pilot gas flow
stops within thirty seconds. Pilot gas safety shutoff
proves complete shutdown because the safety
shutoff valve prohibits main burner and pilot gas
flow.
3.
Relight pilot burner and operate the system
through one complete cycle to ensure all controls
operate properly.
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