VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
F24700 (October 2001) Page 28 of 68
Mechanical Pressure relief v alve factory set to
approximately 15 PSI. I f the pressure in the boiler
reaches this level, the valve will OPEN.
A. High pressure light (amber) will come ON.
1) If the pressure switch opens at a
pressure range other than 14.5 to
15.0 PSI then an adjustment to the
switch setting should be made.
a. Proceed to step 5.
CAUTION: While making the adjustment, do not
press on the wheel with extreme fo rce. The
switch may rotate and develop a l eak at t h e
compression fittings or i n some cases, the rear
lead wire may touch the contro l box and create
an electrical short.
5. Turn the adjustm ent wheel several clicks to
change the pressure switch set point.
A. A counterclockwise rotation lowers the
pressure switch set point while a
clockwise rotation raises the pressure
switch set point.
NOTE: For every cl i ck of the adjustment wheel
during rotation, the pressure setting is changed
approximately 1/8 PSI. Make the adjustment
in small increments.
6. Raise the handle on the 15 PSI mechanical
pressure relief valv e and open the valve f or
approximately 4 mi nut es. This will exhaust
steam down the drain line and lower the boiler
pressure.
A. High limit pressure switch closes at
approximately 12 PSI (non-adj ustable).
1) Press the reset switch to reset the
High Pressure safety control.
a. High pressure light (am ber) goes
out.
B. Lower the boiler pressure to approximatel y
8 PSI.
C. Ignit i on sequence starts, main burner
lights and water in the boiler begins to
heat.
7. Repeat steps 4 through 6 until t he High Limit
Pressure Switch opens at the correct pressure.
8. If the 13 PS I pressure relief valv e (PRV- left
side) was temporarily disabled as outlined i n
step 1:
A. Turn the power switch OFF and allow the
boiler to blowdown.
B. Return the valve to i ts original state.
9. Check steamer f or proper operation.
FILL AND COLD WATERSOLENOID VALVES
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUI T
BOX INDICATING THE CIRCUIT IS BEI NG
SERVICED.
1. Check to ensure the solenoid v alve is receiv ing
power.
A. If the solenoid valv e is receiving power but
the valve is not openi ng, the coil may be
malfunctioning.
1) Remove the lead wires f rom the
solenoid coil and check for conti nuity.
a. If conti nuity is measured,
proceed to step "1. B.".
b. If no conti nuity is measured,
replace the solenoid valv e and
check for proper operation.
B. If the solenoid valv e is receiving power
and the valve appears to be opening but
little or no water is flowing t hrough it, then
the valve ports may be c l ogged with debris
or a valve component m alfunctioning.
2. To check solenoid v alve further, pr oc eed t o
step 3 through 8 for disassembly and inspection
of internal components.
3. Shut water supply off , disconnect the water line
from the valv e body then remove the solenoid
valve from the steamer.
4. Remov e t he coil assembly from the v alve stem
by lifting up on the retai ni ng cap at the top of
the solenoid valve and sli ding the metal cover
plate off.
5. Clamp the body of the valve in a v ise.
6. Mark a scribe li ne on the stem nut to the valv e
body for proper re-tightening.
7. Remov e t he stem locking nut to remov e the
stem from the val ve body.
8. All parts are now accessible f or inspection and
cleaning.
NOTE: If internal sol enoi d parts appear to be
damaged or worn, then replace the solenoid v alve.
Do not reuse damaged or worn parts. No internal
solenoid parts are available as a servi ce
replacement.
A. Check rubber seal on bottom of plunger.
B. Check plunger spring.
C. Check O-ri ng in valve body.