The dishwashing machine must be thoroughly cleaned after each meal or use. The following procedures are to be followed:

1. Turn the machine off.

2. Secure the steam and hot water valves to the final rinse mixing valve, or the steam and hot water valves to the hot water booster heater.

3. Add 3/4 to 1 1/2 cups of dishwashing machine detergent to the rinse tank, depending on the capacity of the rinse tank.

4. Turn the machine on and allow it to operate for 5 minutes.

5. Turn the machine off and secure the steam valve to the rinse tank.

6. Open the drain valves to the wash and rinse tanks; open the doors and allow the machine to cool.

7. Remove the doors, scrap screens, metal frames, wash and rinse spray arms, pump intake strainer, drain strainer, and splash curtains. Wash thoroughly in the utensils wash sink and rinse.

8. Using hand-dishwashing detergent and water with a nylon-bristled brush, thoroughly clean the inside and outside of the machine. Rinse with clean water to remove all loosened dirt and detergent.

9. Reassemble the machine, close the drain valve to the wash and rinse tanks.

10. Fill the tanks one-half full of water, open the steam valve to the rinse tank and allow the temperature to reach 180F.

11. Turn the machine on and operate for 5 minutes without detergent.

12. Turn the machine off, close the steam valve to the rinse tank, and open the drain valves to the wash and rinse tanks.

NOTE: Follow the same basic procedures for the single-tank dishwashing machine with the exception of steps 1 through 4.

DESCALING DISHWASHING MACHINES

The interior of the dishwashing machine and the manifold(s) should be inspected monthly for accumulation of calcium or lime deposits. If deposits are evident, the machine must be descaled.

Descaling the machine should be a part of the PMS and is the responsibility of the foodservice division. The descaling operation must be closely supervised from start to finish, and personnel must wear face shields, chemical safety goggles, rubber gloves, and rubber aprons when handling acid.

These descaling procedures should be followed: 1. Drain wash/rinse tanks, if applicable.

2. Install overflow pipes, scrap trays, screens, spray manifolds (except final rinse), and curtains (inlet and discharge ends only). Place final rinse spray manifold on top of scrap tray in wash tank.

3. Shut drain valves.

4. Fill tanks to within 2 inches of top of overflow pipes with clean hot water.

5. Add 7 fluid ounces of orthophosphoric acid and 1 fluid ounce of rinse additive for each gallon of water per tank. These items can be obtained through the supply system.

6. Complete filling the tanks and close the doors.

7. Start the machine and operate for 1 hour maintaining normal operating temperatures (150F- 160F wash and 180F-195F rinse).

8. Stop the machine and open the drain valves. Completely drain acid solution from machine.

9. Inspect the interior of the machine. All the parts should be free of calcium or lime deposits and metal should be shiny.

10. Repeat steps 3 through 8 if necessary.

11. Close drain valves and fill tanks with clean hot water. Add 2 cups of dishwashing compound per tank.

12. Close doors, start machine, and operate for 5 minutes at operating temperatures.

13. Stop machine and completely drain tanks.

14. Refill and flush tanks with clean water to remove all traces of acid and detergent.

NOTES: (1) In the absence of orthophosphoric acid, only USDA-approved chemicals for descaling machine should be used, follow manufacturer's instruction.

(2) If tank capacity in gallons is unknown, multiply length (inches) times width (inches) times depth to overflow (inches) and divide by 231.

(3) Acid drained from the machine should be disposed of according to local regulations (shore stations and ships in port).