Champion usn-72 Guida Utente

Part 5: BASIC SERVICE

There are two water line strainers on the USN-72 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.

Vacuum Breakers are located at the top of the USN-72 in the 3/4" 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.

A 3/4" water solenoid is located in the final rinse water line at the

outlet of the final rinse booster.  The valve is controlled by the opera-

tion 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.