Burner Orifi Ce; Safety Control Valve; Thermocouple - L.B.White H-17 Manual Del Dueño

Burner Orifi ce
Orifi ce size is stamped on one of the fl ats of the orifi ce
hex. This number indicates size in millimeters.
LP orifi ce: part number 570094, 63 (0.63 mm)
NG orifi ce: part number 570095, 79 (0.79mm)
To access the burner orifi ce:
1. Remove the following:
a. Thermocouple from the safety control valve.
b. Screw and washer from top of air housing
2. Use a 6 mm nut driver to remove the orifi ce from inside
the air housing.
3. If the orifi ce is blocked by dirt, clean with compressed
air. If it cannot be cleaned with air, replace the orifi ce.
DO NOT use tip cleaners, broaches, or small drills
as the hole may be enlarged, creating an overheat
problem.
FIG. 10
Remove screw, washer, and thermocople
Orifi ce
FIG. 11

Safety control valve

The valve contains an electromagnet that receives cur-
rent supplied by the thermocouple when the thermo-
couple is heated.
The current keeps the magnet engaged when you
depress the button on the valve, thereby providing gas
to the emitter. If the magnet internal to the valve is defec-
tive, the heater will light but not stay lit when the button is
released. To replace the safety control valve, refer to the
following procedures and Fig. 12:
H-17 • Radiant Heaters
a. Remove hose and fi lter from the air housing.
b. Remove thermocouple from safety control valve.
c. When replacing, apply pipe thread compound (in-
cluded with replacement) to 1/8 in. threads of safety
control.
FIG. 12
Safety Control Valve

Thermocouple

This works with the safety control valve by supplying direct
current to the valve's magnet when the thermocouple tip is
heated. The thermocouple is positioned at the emitter.
To remove the thermocouple, refer to the following and
Fig. 13.
1. Loosen the thermocouple connector nut at the safety
control valve.
2. Loosen the thermocouple's nut closest to the emitter
while guiding the thermocouple back through the
bracket's hole. Pull the thermocouple from its bracket.
3. When installing the replacement, thread a retaining nut
1 inch from end of thermocouple body. Feed the ther-
mocouple tip partially through the bracket's hole while
threading on the remaining nut. Tighten both mounting
nuts to the thermocouple mounting bracket.
FIG. 13
1 inch
Nut
Owner's Manual • H-17
17
Emitter