![background image](http://html1.mh-extra.com/html/l-b-white/guardian-2-0/guardian-2-0_owners-manual-and-instructions_3183560016.webp)
Guardian 2.0 LP or Natural Gas Heater
www.lbwhite.com
Owner’s Manual • Guardian 2.0
16
Service Instructions
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 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.
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.
Motor & Fan Assembly
NOTE: If disconnecting the motor wires from the harness is
needed, cut and remove the heat shrink tube to ex-
pose the motor wire connections. Replacement of the
heat shrink tubes (574311) after service is necessary
to ensure a corrosion free connection.
1. Remove the motor mounting plate screws and lift the
fan and motor assembly from the housing. See Fig. 14.
(AW250 shown)
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. 14
4. The air pressure switch must not be jumpered. If jump-
ered, the ignition control will not allow heater operation.
Test the air pressure switch for continuity. If defective,
replace the switch.
5. Open the respective case panel for access to burner or
fan related components. Remove the control box lid to
access to the ignition controller, and transformer.
6. Disconnect the appropriate electrical leads when
replacing components.
7. For reassembly, reverse the respective service proce-
dure. Ensure gas connections are tightened securely.
8. After servicing, start the heater to ensure proper opera-
tion and check for gas leaks.
SCREWS
MOTOR MOUNT
PLATE