Figure 4-4. Water heater fuel pump and fuel filter service.

TM-10-3510-208-12 - index
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TM 10-3510-208-12

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. Screw

3. Screw

4. Fuel pump

2. Sump

Figure 4-4. Water heater fuel pump and fuel filter service.

Clean all 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 to 138F. (38 to 59C.).

c. Clean strainer with cleaning solvent, Fed. Spec. P-D-680, and dry thoroughly.

d. Install strainer and new gasket and secure with eight mounting screws (3, fig. 4-4).

Step 2. Inspect fuel pump for loose mounting. Check pumps for cracks, breaks, and leaks.

Tighten the mounting. Replace the fuel pump as follows:

a. Refer to figure 4-5 and remove the fuel filter and bracket.

b. Refer to figure 4-6 and remove the fuel pump.

Step 3. Check fuel pump electric motor for binding or a short circuit that will cause the thermal protector to deactivate.

Reset thermal protector by pressing button located on the end bell of the motor. If the motor does not turn af-

ter resetting, proceed as follows:

a. Shut off the electrical power, open the blower air gate, and try to rotate the motor by inserting a

screwdriver through the air gate opening and turning the blower.

b. If unable to turn the motor, disconnect the fuel pump coupling to determine whether the motor or the

fuel pump is bound. If the pump is bound, fill the pump housing with lubricant and attempt to turn the

shaft with a wrench. If unable to free pump or motor replace defective item.

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