VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
AIR PRESSURE SWITCH
ADJUSTMENT
The air pressure switch senses the pressure level produced by the blower for combustion. When the pressure is sufficient, the switch closes and supplies power to the ignition control module. The gas ignition sequence starts to light the gas pilot and then main burner. If the gas pilot is not lighting (valve not energized), the ignition control module may not be receiving power, assuming the minimum water level is satisfied. Check the air pressure switch operation then adjust if necessary as outlined in the procedure below.
1.Turn the power switch OFF.
2.Remove the left side panel from the cabinet base.
A.Inspect the air intake to the blower for debris build up and clogging.
1)If debris is found, clean it away from the air intake.
B.Turn the power switch ON and verify main burner ignition.
1)If burner ignites then no adjustment to the pressure switch setting is necessary.
2)If burner does not ignite, proceed to step 3.
3.Open the cabinet base door and turn the ON/OFF knob for the main gas valve to OFF.
4.Adjust the air pressure switch setting as follows:
A.Turn the adjustment screw fully clockwise to the highest setting.
B.Slowly turn the adjustment screw counterclockwise until the pilot gas valve energizes then add ½ turn to the adjustment.
NOTE: The screw head should not extend out past the screw housing.
1)If Pilot gas valve energizes, proceed to step 5.
2)If Pilot gas valve does not energize, check the following:
a.Remove the lead wires from the switch and verify with a meter that the switch contacts are closing with the blower ON. If necessary, continue to turn the adjustment screw several turns counterclockwise to CLOSE the switch contacts.
b.If the switch contacts are not closing, turn the power switch OFF, remove the pressure switch from the TEE and check the air orifice for debris build up and clogging. If debris is found, clean it away from the orifice.
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| F24700 (October 2001) |
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