Service Instructions; General; Motor And Fan Wheel Assembly - L.B. White AD100 Owner's Manual And Instructions

Service Instructions

GENERAL

■
Heater surfaces are hot for a period of time after the
heater has been shut down.
■
Allow the heater to cool before performing service,
maintenance, or cleaning.
■
Failure to follow this warning will result in burns
causing injury.
Fire and Explosion Hazard
■
Do not disassemble or attempt to repair any heater
components or gas train components.
■
All component parts must be replaced if defects are
found.
■
Failure to follow this warning will result in fire or
explosions, causing property damage, injury, or
death.
1. Close the fuel supply valve to the heater and disconnect
the electrical supply before servicing unless necessary
for your service procedure.
2. Clean the heater's orifice with compressed air or a soft,
dry rag. Do not use files, drills, broaches, etc. to clean
the orifice hole. Doing so will enlarge the hole, causing
combustion or ignition problems. Replace the orifice if it
cannot be cleaned properly.

MOTOR AND FAN WHEEL ASSEMBLY

1. Remove the screws securing the motor mounting plate
to the fan housing. See Fig.10.
2. Pull the fan and motor assembly from the housing.
3. Loosen the square head set screw(s) on the fan wheel
with a wrench.
4. Pull the fan wheel from the motor shaft. Use a wheel
puller if necessary.
5. Remove the four (4) nuts securing the motor to the
mounting plate.
NOTES: a. Fan wheel to motor mount plate spacing
must be adjusted to 6.4 mm clearance
before tightening the fan wheel to the motor
shaft.
b. Make sure that set screw(s) of the fan are on
the flats of motor shaft when tightening.
12
WARNING
Burn Hazard
WARNING
3. The high limit switch, fuse, and thermostat can be tested
by disconnecting the leads at the component, and
jumpering the leads together.:
-- Reconnect the electrical supply and open fuel
supply valves.
-- If the heater lights, the component is defective
and must be replaced.
-- Do not leave the jumper on or operate the heater if
the part is defective. Replace the part immediately. --
An alternate method for checking the components
is to perform a continuity check..
4. The air proving switch must not be jumpered. If
jumpered, the ignition control will not allow heater
operation. Test the air proving switch for continuity.
If defective, replace the switch
5. Open the respective case panel for access to burner or
fan related components. Open the control box for access
to the ignition controller, relay, transformer, fuse holder,
and reset switch.
6. Disconnect the appropriate electrical leads when
replacing components.
7. For reassembly, reverse the respective service
procedure. Ensure gas connections are tightened
securely.
8. After servicing, start the heater to ensure proper
operation and check for gas leaks.
FIG. 10
FIG. 11
MOTOR MOUNT PLATE
MOTOR
MOUNTING PLATE
SCREWS
FAN WHEEL
CLEARANCE