REPAIR OF HEAT EXCHANGER
The heat exchanger consists of stainless steel stampings welded together to form a maze of passages for the
combustion gases. As these gases flow through the heat exchanger, heat is transferred to the heat exchanger walls
before the gases are exhausted through the exhaust pipe. The flame switch has a tube that extends through a clamp
directly on top of the heat exchanger. Insulation is provided on all sides to reduce heat transfer through the heater case.
(1) Remove the burner assembly from the heat exchanger at the front of the heater. Pull out insulators (1 and 2,
(2) Remove eight screws (3) and lock washers (4) that secure the rear cover (5) to heater case (6).
(3) Remove four screws (7) and lock washers (8) that secure the heat exchanger to the rear cover (5). Remove
the rear cover.
(4) Remove four screws (9) and lock washers (10) from support straps (11), and remove shield (12).
(5) Remove asbestos shield (13), and pull beat exchanger (14) from the heater case.
(6) Remove screws (15) and lock washers (16) from shield retainers (17), and remove shields (18).
(7) Remove four screws and lock washers from the front inside of the heater case to release support straps (19)
and insulator shield (20).
b. Cleaning and Inspection.
Clean parts in a well-ventilated area. Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (fed. spec. P-D-680) used to clean parts is potentially
dangerous to personnel and property. Do not use near open flame or excessive
heat. Flash point of solvent is 100° F (38° C).