VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
F24700 (October 2001) Page 36 of 68
GAS MANIFOLD PRESSURE
ADJUSTMENT
WARNING:
DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING:
SHUT OFF THE GAS SUPPLY
BEFORE SERVICING THE UNIT.
1. Open the cabinet base door to access main gas
valve.
2. Remove the manifold pressure tap plug from
the outlet
side of valve.
A. Install a hose barb adaptor and attach a
gas pressure manometer.
3. Turn the gas supply and power switch ON.
A. Once the boiler fills, press the reset switch
to start the ignition process.
NOTE:
The reset switch can be pressed after
the green ready light on the switch comes ON.
This indicates the water level in the boiler is at
the minimum operating level.
4. After the main burner lights, allow the boiler to
reach operating pressure then compare the gas
manometer pressure reading to the pressure
chart near the end of this procedure.
A. If other appliances are connected to the
same gas line, turn them all ON and check
manometer pressure reading again. If the
pressure drops ½ inch water column or
more, then the gas supply needs to be
checked by the gas line installer or the
local gas company for adequate sizing.
NOTE:
The gas supply line to the steamer
should be a minimum of one inch diameter
(ID).
B. If the pressure does not drop as described
above but the manifold pressure still
requires adjustment, proceed to step 5.
5. Remove the adjustment screw cap to access
the pressure adjustment screw.
6. With the burner lit, set the pressure as outlined
below.
A. To increase pressure, turn the screw
clockwise
.
B. To decrease pressure, turn the screw
counterclockwise
.
NOTE:
Accurate gas pressure adjustments can only
be made with the gas ON and the burner lit.
GAS TYPE
PRESSURE READINGS (INCHES W.C.)
BURNER
MANIFOLD
LINE
MINIMUM
RECOMMENDED
MAX
Natural
3.0 7.0
14.0
Propane
3.0 11.0
NOTE:
If the incoming line pressure is less
than the
minimum stated, then the manifold pressure can not
be set correctly.