Service Instructions; Motor And Fan - L.B. White Guardian AB250 Manuel Du Propriétaire Et Instructions

Service Instructions

WARNING
Burn Hazard
■ 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.
WARNING
Fire and Explosion Hazard
■ Do not disassemble or attempt to repair any
heater components or gas train components
such as gas valves, or gas hoses.
■ 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.
3. The high limit switch and air proving switch
can be tested by:
-- Disconnecting the leads at the compo-
nent, 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.
Guardian LP or Natural Gas Heater
4. Open the respective case panel for access to
burner or fan related components. Open the
control box for access to the ignition controller,
and transformer.
5. Disconnect the appropriate electrical leads when
replacing components.
6. For reassembly, reverse the respective service
procedure. Ensure gas connections are tightened
securely.
7. After servicing, start the heater to ensure proper
operation and check for gas leaks.
Motor & Fan Assembly
1. Remove the motor mounting plate screws and
lift the fan and motor assembly from the hous-
ing. See Fig. 15.
2. Loosen the square head set screw(s) on the
fan wheel.
3. Pull the fan wheel from the motor shaft. Use a
wheel puller if necessary.
4. Remove the four (4) nuts securing the motor to
the mounting plate.
FIG. 15
SCREWS
Owner's Manual • Guardian
19