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 180°F.
11. Turn the machine on and operate for 5 minutes
12. Turn the machine off, close the steam valve to
the rinse tank, and open the drain valves to the wash and
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
manifold(s) should be inspected monthly
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
6. Complete filling the tanks and close the doors.
7. Start the machine and operate for 1 hour
maintaining normal operating temperatures
(150°F- 160°F wash and 180°F-195°F 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,
(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).
Garbage grinders are found in sculleries and deep
sinks. They are used to dispose of food from plates,
unused food items, and other wet garbage. Always read
the operating instructions posted near the grinder before
To clean the tank, dump a bucket of strong, hot
detergent solution into the tank and scrub the interior.
Rinse by flushing the interior walls with hot water.
Clean exterior by scrubbing with hot detergent solution,