CHAMPION USN10 - Manual (Page 54)

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PART 5: BASIC SERVICE
5.3 Component Repair and Replacement (Cont.)
5.3.2 Water Line Strainers
There are two of water line strainers on the USN-10 dishwasher. The first strainer is located on
the 3/4" main water line to the booster. The second is located on the incoming
water line for the tank fill. The line strainer screen may become clogged with
debris. To clean the strainer screen: Turn off the main water supply valves.
Open the tank fill manual valves to bleed off pressure. Run a dishrack through
the machine to operate the final rinse and bleed off water pressure at the booster.
Turn power off at the dishwasher control cabinet. Remove the locknut at the
end of each strainer "Y". Remove the strainer screen and flush clean with water.
Reinstall in reverse order. Turn on water supplies and check for leaks.
5.3.3 Vacuum Breaker Repair
Vacuum Breakers are located at the top of the USN-10 in the 1/2" final rinse water line and each
of the 1/2" tank fill lines. They prevent the siphoning of dish-machine water back into the
potable water supply. Each vacuum breaker contains a moveable float. To replace the float:
Turn off the main water supplies. Turn off the power at the dishwasher control switch. Unscrew
the top of the vacuum breaker. Remove the float. Inspect the interior of the vacuum breaker.
Remove any mineral deposits and inspect the float seating surfaces for pitting. (If badly pitted,
replace the entire vacuum breaker assembly). Install a new float repair kit and reassemble in
reverse order. Turn on power and water supplies. Operate the dishwasher and check for leaks.
5.3.4 Water Solenoid Valve Repair
A 1/2" water solenoid is located in the final rinse water line at theoutlet of the
final rinse booster. The valve is controlled by the operation of the final rinse
switch assembly which connects 120VAC to the valve coil during a final rinse
operation. If the valve fails to operate, first check that 120VAC is supplied to
the valve coil. If voltage is not present, then refer to the electrical schematic
and troubleshoot the circuit. If voltage is present then the valve may require a
rebuild kit or replacement coil. Turn off power at the dishwasher power switch
and main disconnect. Turn off main incoming water supply and bleed off any
water pressure in the line. Check the coil for continuity with a VOM set at the
highest resistance range. If the coil checks good then disassemble the valve by
unscrewing the threaded bonnet with a strap or spanner wrench. Remove and
inspect the valve piston and diaphragm. Inspect the valve seat for mineral deposits and pitting.
(Replace the complete valve assembly if pitting is severe). Reassemble the valve in reverse order.
Turn on power and water supplies and check for leaks.