L.B. White 170 Dual Fuel - Manual (Page 18)

1. Open the burner end access doorand remove gas
hose from heater.
2. Remove the elbow and all screws at inlet of gas
control valve. See Fig. 21.
FIG. 21
3. Remove the burner retaining bolt at the underside of
the heaters base. The bolt is accesible through an
opening in the heater’s support leg. Use a ratchet
with extension and 9/16 in. socket. See Fig. 22.
FIG. 22
4. Pivot the gas control assembly to expose the burner
orifice. See Fig. 23. Replace components as needed.
FIG. 23
5. When assembling the control valve to manifold, the
valve must be offset 8 degrees from the orifice holder
to ensure the control valve aligns to its mounting
holes. See Fig. 24.
FIG. 24
BURNER ORIFICE, SELECTOR VALVE & CONTROL VALVE
This heater has two limit switches. One is located on the
heat chamber, the other on the fan housing. In an overheat
condition, either swtich will trip, removing power to the gas
control valve. The switch must be reset by firmly pressing
its reset button.
To maintain safe operation, both switches should be tested
annually, typically when the heater is given a thorough
cleaning.
1. Remove either high limit switch.
2. Holding the switch by one of its mounting legs, apply
a small flame only to the sensing portion on the back
of the switch. Be careful not to melt the plastic
housing of the switch when conducting this test.
3. Within a minute, you should hear a pop coming from
the switch, indicating the contacts of the switch have
opened.
4. Allow the switch to cool for about a minute before
firmly pressing its reset button. The switch may have
a red cap over the button. If you removed the cap to
reset the switch, ensure you put it back on.
5. Check for electrical continuity across the switch
terminals to make sure the contacts have closed.
FIG. 20
TESTING THE MANUAL RESET HIGH LIMIT SWITCHES
WARNING
Fire Hazard
■
Do not operate the heater with the high limit switch
bypassed.
■
Operating the heater bypassed high limit switch may
lead to overheating, possibly resulting in a fire, with
subsequent damage to the heater or property damage.
RESET BUTTON
SENSING
SURFACE
TERMINAL
FLAME
MOUNTING
LEG
BOLT
BYNAME/JIMI/TS170B/TS170-02
ORIFICE
HOLDER
GAS
CONTROL
8°
ORIFICE
18