f. Adjustment. Adjust the impeller by installing or
a. Description. The water pump is mounted inside
Install shims until the impeller will rub against the vane
the water pump frame, and is operated by an electric
plane when it is installed. Remove 0.004 shim and
motor. It draws water through the suction strainer and
install impeller and vane plate. The impeller should turn
the hose, from the water source, and forces it through
freely without rubbing against the vane plate after the
the discharge hose to the water heater. On the pump
proper adjustment has been made.
housing a drain cock is located. It is used to drain the
g. Installation. Install the water pump drain cock
water from the pump.
by reversing the procedures in b above.
(1) Remove the electric motor and the pump
a. Control Panel Circuit Breaker Subassembly.
(2) Remove the nuts from the studs that hold
the pump housing (9, fig. 4-10) to the bracket (5).
subassembly is a switch device which stops the flow of
current in a continuous circuit when the circuit is
overloaded. The instructions in this paragraph pertain to
the circuit breaker subassembly either on the water
(4) Unscrew and remove the water line
heater or the water pump.
tee (13) from the housing (17).
that secure the control panel box cover to the box, and
from the bracket (26), and remove the impeller (23)
separate the cover from the box.
(b) Remove the screws that secure the
(6) Remove the shims (6), washer (24),
circuit breaker subassembly to the cover, and separate
mechanical seal (5), stationary seals (4 and 25) from the
the subassembly from the cover.
(7) Unscrew and remove the drain cock (8,
subassembly over to expose the wire connections as
(d) Loosen the screws that attach the
(1) Inspect the housing for breaks, cracks and
wire connections to the circuit breaker subassembly.
(e) Remove the wires from the circuit
(2) Inspect for broken, cracked or dirty
impeller and vane plate.
(3) Examine the mating surfaces of the seals
Tag the wires for identification if
to see that they are highly polished, and are not pitted,
color-coded wires are not used.
scratched and corroded.
(3) Inspection. Use an ohmmeter to check
(4) Inspect the drain cock for broken handle
for continuity across the terminals with the switch in the
and damaged threads.
ON position. Inspect for damaged threads and broken
d. Servicing. Clean dirt and foreign matter from
the impeller and the vane plate.
Replace defective circuit
e. Repair. Replace a defective pump housing,
breaker subassembly with a serviceable one and install
vane plate or impeller. Repair the water pump by
it by reversing the procedure in a (2) above. Connect
installing a new water pump repair kit.
the wires according to the wiring diagram in figure 4-15
for the water pump.