Despite your best efforts, sometimes your commercial dishwasher does not clean the dishes completely. The following table shows the most common reasons for dirty dishes and possible solutions:
Symptoms
Possible Cause
Suggested Solution
Dishes Still Dirty
Insufficient Detergents
Use enough detergent in wash water to ensure complete soil removal
Wash water temperature too low
Keep water temperature within recommended ranges to dissolve food residue and to further facilitate heat accumulation for sanitization
Inadequate wash and rinse times
Allow sufficient time for wash and rinse operations to be effective
Insufficient prewashing
Do a better job of removing leftovers and food waste prior to running dishes through machine
Using low temp machine
Switch to high temperature sanitizing machine
Improper racking or placement
Rack dishes according to size and type in appropriate rack
Films
Water Hardness
Use a chlorinated cleaner
Use external softening process
Use more detergent to provide internal conditioning
Check temperature of wash and rinse water, verify that it is not outside recommended range
Detergent Carryover
Maintain adequate pressure and volume of rinse water
Improperly cleaned or rinsed equipment
Adopt frequent and adequate cleaning practices
Maintain adequate pressure and volume
Greasy Films
Low pH
Maintain adequate alkalinity to dissolve greases
Insufficient detergent, Low water temperatures
Check amount of detergent and water temperature
Improper cleaning
Unclog all wash and rinse nozzles to assure proper spray action
Streaking
Alkalinity in water
Use external treatment method to reduce water alkalinity
Spotting
Rinse water hardness
Provide internal or external water softening
Rinse water temperature too low or too high
Check rinse water temperature to assure water is drying off dishes not drying on them
Inadequate time between rinsing and storage
Allow sufficient time to air dry
Foaming
Detergent
Change to a low sudsing product
Water too soft or too hard
Use an appropriate treatment method to adjust water condition
Food soil
Adequately remove leftovers before washing
Wash temperature too low
Increase water temperature