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VL SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
D.
With the thermocouple disconnected,
connect the meter leads to the tube and
threaded end. Turn the power switch ON
and light the pilot. Hold down the
OFF/PILOT/ON knob and allow the pilot to
heat the thermocouple for one to two
minutes. Take an open circuit reading and
compare with the chart below.
1)
If the reading is less than the
minimum or thermocouple is not
operating as described, replace the
thermocouple as outlined under
"PILOT AND THERMOCOUPLE
ASSEMBLY (GAS MODELS)" in
"REMOVAL AND REPLACEMENT
OF PARTS" then check for proper
operation.
3.
If after checking and/or replacing
thermocouple, the pilot or main burners are still
not functioning properly, then a problem in the
gas combination control valve exists as well.
Replace the combination control valve as
outlined under "GAS COMBINATION
CONTROL VALVE" in "REMOVAL AND
REPLACEMENT OF PARTS" then check for
proper operation.
NOTE: Gas combination control valves are not
serviceable and should not be disassembled. Once
you have isolated the problem to this control,
replace it. Do not attempt to repair the assembly.
THERMOCOUPLE
DC MILLIVOLT
READINGS
CLOSED CIRCUIT
(CONNECTED)
Typical
15
Range
10 - 20
GAS BURNERS
The main gas burners are located under the boiler
for heating and number five to seven depending on
the steamer model. They are made of aluminized
steel with lanced type ports and have adjustable air
shutters in the front. Fixed orifice type hoods extend
from the manifold to establish gas flow to each
burner.
Air Shutter Adjustment
1.
Ignite the burners and allow to heat up for at
least five minutes.
2.
Verify the manifold pressure as outlined under
"GAS MANIFOLD PRESSURE
ADJUSTMENT".
OPEN CIRCUIT
(DISCONNECTED)
20 - 35
Page 31 of 88
3.
Loosen the set screw on the burner being
adjusted. Closing the air shutter will decrease
primary air to the burner and opening the
shutter will increase primary air the burner.
4.
Monitor the burner flame and set the air shutter
opening as follows:
A.
Open up the air shutter until the inner
portion (blue) of the flame lifts off the
burner port and then turn the air shutter
back until the flame touches the burner
port again. A slight tinge of orange and
yellow in the flame is acceptable. An
extremely yellow flame indicates too little
primary air (oxygen), producing poor
burning characteristics and the heating
efficiency drops off. A by product of this
would be soot (carbon).
Factory air shutter settings are: natural
gas - open approximately ½ inch;
propane gas - fully open.
5.
After the air shutter adjustment is made, tighten
the set screw.
Inspection
Remove gas burners by lifting burner up and sliding
it to the rear just enough to clear the gas orifice
hood. Lower the front end of burner and bring it
forward under the gas manifold pipe. Inspect burner
for clogged or damaged ports. Clean or replace as
necessary. When reinstalling burners, assure that
locating pin is in the hole for proper positioning and
to prevent burner from rolling over.
AUTOMATIC IGNITION SYSTEMS
(GAS MODELS)
When the main power switch is turned ON and the
ignition control modules reset switch is in the ON
position, the ignition control module is energized
with 24VAC between terminals five and six.
High voltage is sent from terminal nine to the spark
electrode and an output of 24 volts is sent from
terminals two and three to the pilot coil in the
combination valve, allowing gas to flow to the pilot.
The sparking will continue for 90 seconds or until
the flame sensor has confirmed that an adequate
pilot flame is present.
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