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VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
WATER LEVEL CONTROL(S)
TEST
Loose electrical connections may prevent the heat
from coming on or may cause the boiler to overfill.
An accumulation of lime scale on or near the water
level sensing probes may cause them to retain
water (moist) on the probe surface and give a false
reading. Also, a cracked or damaged insulator may
give a false reading. These conditions may prevent
the boiler from filling or cause dry firing. Dry firing
will result in damage to the heating elements on
electric models or to the boiler on gas or electric
models.
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
Solid State - Low level Cut-Off & Differential
Control
1.
Turn the power switch ON.
2.
Ensure that water is filling the boiler.
A.
Confirm that water supply valve(s) are
turned on.
B.
Observe boiler water level in the water
level gauge. If empty, boiler should fill in
approximately 11 minutes.
3.
Check the voltage across terminals L1 & L2 on
the board. Meter should read 120VAC.
A.
If voltage is correct then the high level
(HL) relay should energize, closing HL-3
contacts and the HL LED should light up.
The boiler fill solenoid should then
energize and start filling the boiler. Verify
boiler fill solenoid valve is receiving
120VAC and water is flowing through it.
B.
If boiler fill solenoid is receiving power but
no water is flowing, inspect fill solenoid for
malfunction or valve for clogged ports. If
solenoid is bad or ports can not be
cleaned, then replace boiler fill solenoid
and check for proper operation.
C.
If boiler fill solenoid is not receiving power
and the electrical connections have been
checked, then the HL relay is not being
energized or the HL-3 contacts are not
closing. Replace water level control board
and check for proper operation.
4.
If boiler is filling properly, when the water level
reaches the low level cut-off (LLCO) probe,
LLCO relay should energize closing LLCO-2
contacts, heat source should come on
(standard models only) and LLCO LED will
light.
5.
Once the water level reaches the high level
(HL) probe, the inverse latching relay of the
board (solid state) should energize and lock
through the low level probe (LL) and ILR-1
contacts. With ILR-2 contacts open, the HL
relay is de-energized and HL LED goes out.
With the HL-3 contacts open, the boiler fill
solenoid should de-energize and stop the boiler
fill.
6.
If water is in the boiler but is not being detected
by the water level probes, the probes may need
cleaned and/or boiler delimed. See "Water
Level Probes" as outlined below for inspecting
and cleaning of probes and "BOILER" for a
procedure on boiler inspection, clean-out and
deliming.
7.
Turn the power switch OFF and disconnect the
lead wire from each probe. Check the probes
as outlined below.
A.
With an ohmmeter, check between the
probe terminal and boiler shell. An open
circuit should be present when the boiler is
empty. If resistance is present, remove
and inspect the probes as outlined below
under "Water Level Probes". When the
boiler is full of water, a resistance reading
should be measurable between the probes
and boiler.
NOTE: The actual resistance reading will depend on
water quality and probe condition.
8.
After performing steps 1-5A and verifying the
water level control boards operation, if the
control is not functioning as described, then
replace it and check for proper operation.
Electro Mechanical - Low level Cut-Off &
Differential Control
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
1.
Ensure that water is filling the boiler.
A.
Confirm that water supply valve(s) are
turned on.
B.
Observe boiler water level in the water
level gauge.
C.
Verify boiler fill solenoid valve is receiving
120VAC and water is flowing through it.
2.
Check for correct voltage being applied to the
low level and differential water level controls.
A.
Turn the water supply valve off then turn
the power switch ON. Check the input
voltage across terminals 1 & 2. Meter
should read 120VAC. If voltage is correct
proceed to step 2B. If voltage is incorrect,
find the source of the problem and repeat
this step.
Page 24 of 88
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