VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
F24700 (October 2001)Page 29 of 68
D. Check ports in valve body.
9. Reverse procedure to install.
BOILER BLOWDOWN/DRAIN
SOLENOID VALVE
The water contained in the boiler, being under
pressure, should be "blown through" this valve and
be noticeably visible exhausting out the steamer
drain. Daily boiler blowdown is essential
to proper
operation and component life by removing sediment
and scalants that may be lodged in the chamber of
the boiler.
The boiler blowdown/drain process is an automatic
function and should start whenever the power switch
is turned OFF after a normal operating cycle. The
blowdown solenoid is a normally open (N.O.) valve
that CLOSES when energized by the power switch.
When the power switch is turned OFF, the
blowdown solenoid is de-energized and the valve
OPENS to allow the boiler to blowdown.
If the blowdown operation appears to function
sluggishly or not at all, considerable scalants may
be lodged in the drain line plumbing exiting the
boiler, strainer, and/or the blowdown valve.
1. Turn the power switch OFF and allow boiler to
blowdown.
2. Turn the ON/OFF knob on the main gas valve
to OFF.
3. Remove the strainer clean-out plug located in
the center of cap.
4. Turn the power switch ON and allow the boiler
"fill water" to flush-out the drain line until no
debris is seen exiting the clean-out hole.
5. Turn the power switch and the water supply
OFF.
6. Turn the ON/OFF knob on the main gas valve
back to ON.
7. Remove and clean the strainer as outlined
under "INLINE WATER STRAINER
CLEANING".
A. If the boiler blowdown is ok, then the drain
line and valve are clear of debris and the
valve is functioning properly.
B. If considerable lime scale debris is
apparent, then not only the blowdown
valve, but also the boiler and water level
probes must be thoroughly cleaned. See
"FILL AND COLD WATER SOLENOID
VALVES" for an inspection and cleaning
procedure of a solenoid valve and
"BOILER" for a procedure on boiler
inspection, clean-out and deliming.
INLINE WATER STRAINER
CLEANING
The procedure outlined below can be used to
inspect and clean the inline water strainer for the
blowdown solenoid valve and, if installed, the inline
water strainer for the boiler fill solenoid valve. Inline
Y strainers should always be located upstream of a
water solenoid valve.
NOTE:
For proper operation, the strainer must be
installed so the water flow is directed towards the
solenoid valve and the leg of the Y with a threaded
cap is pointing downwards to catch debris.
1. Turn the power switch OFF to and allow the
boiler to blowdown.
2. When blowdown completes, shut OFF the
water supply.
3. Remove the cap and strainer screen from the
leg of the Y pointing downwards toward the
floor.
4. Remove the screen from the cap and clean any
accumulated debris from the screen and also
remove any debris trapped in the opening of
the strainer body.
NOTE:
If screen can not be thoroughly cleaned,
replace it with a new one.
5. Insert screen into cap then re-install cap to
strainer body.
6. Turn the water supply and power switch ON
and allow the boiler to reach operating
pressure.
7. Turn the power switch OFF and check strainer
for leaks, as the boiler blows down.