Service Instructions; General; Motor, Fan, And Air Proving Switch - L.B. White CP400 Owner's Manual And Instructions

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Some heater surfaces are hot for a period of time
after the heater has been shut down.
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Allow the heater to cool before performing service,
maintenance, or cleaning.
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Failure to follow this warning will result in burns
causing injury.
Fire and Explosion Hazard
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Do not disassemble or attempt to repair any heater
components or gas train components.
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All component parts must be replaced if defects are
found.
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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. Remove the heater's bottom base or side panel for
access to electrical components and connections.
3 Disconnect the appropriate electrical leads for the
component being replaced.
1. Remove the fan guard and the screws securing the
motor mount to the heater's barrel. See Fig. 7.
2. Lift motor/fan assembly from heater.
FIG. 7
FAN END
OF HEATER
REMOVE FROM BOTH SIDES
Motor
-- Remove both screws and strap securing the motor.
Air Proving Switch
-- Remove screw securing switch bracket to motor mount.
-- On reassembly, ensure tab on switch bracket is located in
positioning hole adjacent to screw hole.
WARNING
Burn Hazard
WARNING

Service Instructions

4. Remove the fan guard and motor/fan assembly for
access to upper barrel components.
5. The auto reset backflash, and thermostat can be
tested by disconnecting the leads at the component,
and placing a jumper connecting 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.
6. 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
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.
9. Clean the heater's orifice with compressed air or a
soft, dry rag. Do not use files, drills, broaches, etc. to
clean the orifice. Doing so may enlarge the hole,
causing combustion or ignition problems. Replace
the orifice if it cannot be cleaned properly.
MOTOR , FAN, AND AIR PROVING SWITCH
Fan
-- Loosen set screw at hub.
-- Pull fan from shaft.
-- Ensure fan is flush on shaft end, and set screw is
positioned over flat of motor shaft before tightening
FIG. 8
REMOVE
SCREWS

GENERAL

SET SCREW
AIR PROVING
SWITCH
12 14