CHAMPION USN72 - Manual (Page 60)

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Part 5: BASIC SERVICE
5.3.5 Float Switch Replacement
Refer to Fig. 6.12, C , Part 6, Replacement Parts, for a detailed drawing of the float switch assembly.
Each tank contains a float switch assembly which monitors the water level in the tank. When the water
level drops below a preset level the ball on the float switch stem drops and opens a reed switch. The
control relay associated with the float switch changes state. A set of normally closed contacts open
interrupting power to the 120VAC control circuit and the dishwasher stops. If you suspect a defective
float switch: Turn power off at the dishwasher control cabinet. Drain the tank and inspect the float.
Make sure the float is clean and moves freely. Identify the float switch wires in the junction box located
on the lower corner of the dishwasher front. Disconnect the float switch and connect its associated
control wires together. Turn power on and restart the dishwasher. If the dishwasher operates normally,
then replace the float. To remove the float assembly: Remove the float switch cover. Remove the
5/16-18 nut on the outside of the tank. The mounting hole is keyed so the float switch will not turn.
Remove the float switch assembly from the inside of the tank. Install a replacement in reverse order.
Reconnect the float switch wires in the junction box. Turn power on, refill the tank, and test the
dishwasher for normal operation.
5.3.6 Drain Valve and Overflow Assembly
Refer to Fig. 6.15, Part 6, Replacement Parts, for a detailed drawing of the drain and overflow assembly.
Note items 1-4. These parts make up the overflow assembly. The assembly consists of an overflow tube
with drain box topped by a hinged cover. The cover tilts up to allow inspection and cleaning. Lift up the
hinged cover and inspect the overflow tube if an obstruction is suspected. Item 10 shows the drain screen.
This screen should be inspected daily and cleaned. Item 12 illustrates the drain assembly. It consists of
soldered copper pipe and if defective must be replaced as a unit. Note the cleanout plug to the left of the
drain valve. This plug can be removed to clean possible obstructions from the drain assembly. Item 13
shows the 1-1/2" cleanout plug in the drain trunk line. Remove the plug to inspect and clean the main
dishwasher drain line.
5.3.7 Thermometer Replacement
Refer to Fig. 6.12, Part 6, Replacement Parts, for a detailed drawing of the thermometer assemblies. The
thermometers are mounted to brackets on the top of the dishwasher*. Thermometer capillary tubes run
from the top of the dishwasher to the right and left ends of the tanks. The thermometer bulbs are retained
inside the tanks by a 1/2" locknut. The final rinse thermometer bulb mounts directly into the upper final
rinse piping at the top of the dishwasher. Tank and final rinse thermometers are factory sealed indicating
devices which are accurate within ±3° of the intended range of use. The thermometers cannot be cali-
brated and must be replaced if defective. To replace a thermometer: Drain the machine and turn off all
power. Have a helper hold the thermometer bulb from the outside of the machine. Remove the 1/2"
locknut from the inside of the tank and pull the thermometer sensor bulb out of the tank. Remove the nuts
and retainer from the thermometer bracket. Pull the thermometer out the front of the bracket. Replace the
thermometer and reassemble in reverse order. Be sure to apply plumber's putty, (Champion P/N 104889),
to seal the thermometer bulb fitting in the tank. Return the dishwasher to normal operation and check the
temperature reading.
* Wash tank and rinse tank thermometers are located on the lower front side of the wash and rinse tank.
The final rinse thermometer is located in the final rinse piping at the top of the dishwasher.