L.B. White 250 Norseman - Manual (Page 12)

Service Instructions
A. General
1. Close fuel supply valves to heater and allow heater to
burn off remaining fuel in its hose before servicing,
unless it is necessary to have the valves open for the
service procedure.
2. Clean the heater’s orifices with compressed air or a
soft rag. Do not use files, drills, broaches, etc. to
clean the orifice hole. Doing so will enlarge the hole,
causing ignition or combustion problems. Replace
the orifice if it cannot be cleaned properly.
3. Reverse the respective ser vice procedure to
reassemble. Ensure gas connections are tightened
securely.
4. After repair, light the heater. Check for proper
operation and for gas leaks.
B. Initial PPreparation
1. Remove burner retaining bolt from heater base.
2. Remove burner assembly from case.
C. Burner O Orifice R Removal
1. Disconnect compression nut from brass elbow and
thermocouple from pilot control valve. See Fig. 4.
2. Carefully reposition pilot line and thermocouple away
from safety control valve.
3. Disassemble the following: See Fig. 5.
-- Pilot control with manual valve from burner
orifice
-- Burner orifice from burner casting
4. Clean the burner orifice.
FIG. 4
FIG. 5
D. Pilot O Orifice
1. Loosen compression nut at pilot orifice and carefully
reposition pilot tube away from the orifice. See Fig. 6.
2. Remove pilot orifice from pilot head and screen from
orifice inlet.
3. Ensure orifice hole is not plugged.
E. Thermocouple
1. Loosen attachment nut at pilot assembly and
connector nut at safety control valve. Remove
thermocouple. See Fig. 6.
2. At reassembly, avoid sharp bends or kinks in
thermocouple to prevent damage.
FIG. 6
NUT
BURNER ORIFICE
THERMOCOUPLE
SCREEN
PILOT ORIFICE
PILOT HEAD
BRACKET ASSEMBLY
ATTACHMENT NUT
CONNECTOR NUT
WARNING
Burn H Hazard
■ Heater surfaces are hot for a period of time after
shutdown.
■ Allow heater to cool before servicing.
■ Failure to follow this warning can result in burns.
WARNING
Fire aand EExplosion H Hazard
■ Do not disassemble or attempt to repair any heater
component, including gas hose and regulators.
■ All components must be replaced if defects are found.
■ Failure to follow this warning will result in fire or
explosions leading to property damage, serious injury,
or death.
BURNER
VALVE
VALVE
ELBOW
BURNER ORIFICE
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