Commercial Commercial Dishwasher: Spotting — Causes & Fixes

1. Turn the machine off and, if it holds water, drain it (lift the drain ball/actuator until the water is out).
2. Lift out the drain/scrap screen and remove any foreign object (a stuck knife, fork, or spoon) from the drain area.
3. Rinse all food debris off the screen at the sink or with the pre-rinse hose - do not bang it on the table to knock food loose.
4. Remove and rinse the scrap tray/accumulator drawer; clean it after each meal, or hourly when very busy.
5. Reinstall the screen in its proper position in the sump housing before refilling.

· Tools: Sink or pre-rinse hose, Disposable gloves · Source: CMA EAH/EC Owner's Manual (Cleaning the drain screen; Machine Will Not Hold Water; Empty the Scrap Tray)

1. Turn the machine off and remove the upper and lower wash/rinse arms per your manual.
2. Hold each arm and check that water would blow from every jet; use a toothpick to open any clogged jet - do not enlarge or gouge the openings.
3. If an arm is still restricted, unscrew the stainless end plug and flush the inside of the arm tube at the sink to clear scraps.
4. Rinse the arms clean, reinstall the end plug hand-tight, and reseat the arms fully so they spin freely and spray reaches all ware.
5. Run a test cycle and confirm even spray from both arms.

· Tools: Toothpick or soft pick, Sink for flushing, Disposable gloves · Source: CMA EAH/EC Owner's Manual (Cleaning the washer arms); Champion UH130 (clean spray arms)

1. Confirm each color-coded pick-up line is in the correct container (on CMA: red = detergent, blue = rinse aid, clear/white = sanitizer) with tube stiffeners in place so the tube can't curl and suck air.
2. With the master switch ON, hold each prime switch until product runs through the line and discharges into the sump/injection point (no air bubbles).
3. Run one full cycle and watch each injection tube to confirm detergent, rinse aid, and sanitizer are all feeding.
4. On low-temp machines, test the final rinse at the surface of the ware with chlorine strips - it should read at least 50 ppm (target 50-100 ppm).
5. If concentration is off, adjust the pump feed (CMA uses adjustable cams) or call your chemical supplier; never exceed a 6% sodium hypochlorite solution.

· Tools: Fresh chemical containers, Chlorine test strips (low-temp machines), Disposable gloves · Source: CMA EAH/EC Owner's Manual (Chemical Feeder; Activating Machine; Check Operations; 50-100 ppm)

1. Identify your machine type from the data plate: high-temperature (hot-water sanitizing) or low-temperature (chemical sanitizing).
2. High-temp: run a rack and check the final rinse reaches at least 180°F at the manifold (165°F for a stationary-rack single-temperature machine); confirm the utensil surface reaches 160°F using a maximum-registering thermometer or heat-sensitive label placed on a plate through the cycle.
3. Low-temp: run a cycle and test the final rinse at the ware surface with chlorine strips; it must read at least 50 ppm (target 50-100 ppm).
4. Record the reading per your health department's practice.
5. If the machine can't reach sanitizing temperature or concentration, stop using it to sanitize, manually wash-rinse-sanitize ware in a three-compartment sink, and call for service.

· Tools: Chlorine test strips (low-temp), Maximum-registering thermometer or heat-sensitive temperature label (high-temp) · Source: FDA Food Code 4-501.112 (hot water), 4-501.114 (chemical), 4-703.11 (utensil surface 160°F); CMA (50-100 ppm)

1. Confirm scale is the problem: white chalky film on tank walls, arms, jets, or booster, usually with hard water.
2. For light routine scale, follow the deliming instructions in your machine's own manual exactly, using only the manufacturer-approved delimer, with gloves and eye protection, and rinse thoroughly.
3. Do not mix delimer (acid) with detergent or sanitizer (chlorine) - mixing acid and bleach releases toxic gas.
4. Heavy scale, or deliming the booster heater and internal plumbing, uses highly caustic agents - have a qualified chemical specialist do it.
5. Prevent recurrence with water treatment to about 3.5 grains-per-gallon or softer and keep the softener charged with salt.

· Tools: Manufacturer-approved deliming product (per label), Chemical-resistant gloves and eye protection, Water-hardness test · Source: CMA EAH/EC Owner's Manual (de-liming agents are highly caustic; must be done by a qualified chemical specialist; water softening to 3.5 gpg)