Service Instructions; Motor And Fan Assembly - L.B. White Guardian Series Owner's Manual And 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 fi re 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 orifi ce with compressed
air or a soft, dry rag. Do not use fi les, drills,
broaches, etc. to clean the orifi ce hole.
Doing so will enlarge the hole, causing
combustion or ignition problems. Replace
the orifi ce if it cannot be cleaned properly.
3. The high limit 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 with Smart Sense™
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 continu-
ity. 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,
transformer, and signal conditioner.
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.
Motor & Fan Assembly
1. Open louvered access panel opposite burner
end of heater. Disconnect motor leads.
2. Remove all screws securing motor mounting
plate to housing.
3. Pull fan and motor assembly from housing.
4. Loosen set screws on fan wheel.
5. Pull fan wheel from motor shaft.
6. Remove the four nuts securing motor to mount-
ing plate
FIG. 10
SCREWS
Owner's Manual • Guardian
MOTOR MOUNT PLATE
19