How to Clean and Maintain Your CMA Dishmachine

What CMA Dishmachines Are and Why They Matter

CMA dishmachines are commercial-grade dishwashers built for high-volume kitchens—restaurants, cafeterias, hospitals, and catering operations. Unlike home dishwashers, they're engineered to handle hundreds of place settings per shift, with faster wash cycles, hotter water, and more powerful spray jets. If you own or operate one, keeping it clean and well-maintained directly affects food safety, energy costs, and how long the machine lasts.

CMA Corporation manufactures several models, from undercounter machines to conveyor systems. Each has different cleaning needs and maintenance schedules, but the core principle is the same: regular cleaning prevents mineral buildup, grease accumulation, and bacterial growth that can compromise both performance and hygiene.

Key Takeaways

• Daily cleaning of the wash tank, spray arms, and strainer basket prevents grease and food debris from blocking water flow and reducing wash quality.
• Weekly deep cleaning of the interior surfaces, door seals, and detergent dispensers removes mineral deposits and buildup that reduce machine efficiency.
• Monthly descaling with a commercial dishwasher cleaner removes hard water deposits that accumulate inside the heating elements and spray system.
• Checking water temperature and pressure weekly ensures the machine is operating at the settings required by health codes and the manufacturer.
• Replacing or cleaning the strainer basket and checking door gaskets monthly catches small problems before they become expensive repairs.

Daily Cleaning Tasks That Keep Your CMA Running

Start each shift by emptying and rinsing the wash tank strainer basket. Food particles, grease, and debris collect here and block water circulation if left to accumulate. Remove the basket, rinse it under hot running water, and use a soft brush to clear any stubborn buildup. This five-minute task prevents clogs that can force the machine to work harder and use more water.

Wipe down the interior walls of the wash tank with a damp cloth or soft sponge. Grease and detergent residue stick to stainless steel surfaces and reduce the reflectivity of the tank, which means less effective spray coverage. Pay special attention to corners and seams where debris tends to hide. If you notice a film or discoloration, use a cloth dampened with white vinegar to cut through the buildup.

Check the spray arms—both upper and lower—for clogs. Food particles can lodge in the spray holes and reduce water pressure. Hold each arm up to a light and look through the holes. If you see blockages, use a straightened paper clip or a small pipe cleaner to clear them gently. Never use a toothpick or anything that might crack the plastic or metal.

At the end of each shift, run a rinse cycle with no dishes in the machine. This flushes out loose food particles and detergent residue before they dry and harden overnight. Leave the door open for 15 to 20 minutes to allow the interior to air-dry and prevent mold or odor buildup.

Weekly Deep Cleaning and Inspection

Once a week, remove the spray arms completely and soak them in hot water with a commercial dishwasher cleaner for 20 to 30 minutes. This dissolves mineral deposits and grease that daily rinsing misses. Use a soft brush to scrub the exterior, then use a thin wire or pipe cleaner to clear each spray hole from the inside. Rinse thoroughly under hot water before reinstalling.

Inspect the door gasket—the rubber seal around the door edge. Food particles and mineral deposits can accumulate here and prevent the door from sealing properly, which allows water to leak during the wash cycle. Wipe the gasket with a damp cloth and a small amount of white vinegar. If you see cracks, hardening, or permanent indentations, note it for replacement during your next maintenance window.

Clean the detergent and rinse aid dispensers. Open the access panels and wipe out any dried or caked detergent. Rinse the dispenser cups with hot water and a soft brush. Refill both dispensers to the manufacturer's recommended levels. If the dispenser mechanism seems stuck or slow to release, soak the dispenser cup in hot water for 10 minutes to loosen buildup.

Wipe down the exterior surfaces, including the control panel and door handle. These areas collect fingerprints, grease splatter, and dust. Use a damp microfiber cloth and a stainless steel cleaner if the exterior is stainless steel. Avoid abrasive scrubbers that can scratch the finish.

Monthly Descaling and Maintenance Checks

Hard water deposits accumulate inside the heating elements, spray system, and water lines over time. These deposits reduce water temperature, slow water flow, and force the machine to work harder, which increases energy use and shortens the machine's lifespan. Once a month, run a descaling cycle using a commercial dishwasher descaler formulated for CMA machines.

Follow the manufacturer's instructions for your specific model. Most descaling processes involve filling the wash tank with a diluted descaling solution, running a full wash cycle with no dishes, then running two or three rinse cycles with clean water only. This removes mineral buildup from the heating elements and internal plumbing. Do not skip the rinse cycles—residual descaler can affect wash quality and leave a taste on dishes.

Check the water inlet filters. These small screens prevent sediment and debris from entering the machine's water lines. If your facility has hard water or older plumbing, sediment can accumulate quickly. Turn off the water supply to the machine, disconnect the inlet hose, and remove the filter screen. Rinse it under running water and use a soft brush to clear any trapped particles. Reinstall and reconnect the hose.

Test the water temperature with a calibrated thermometer. Most commercial dishwashers require a minimum of 140°F (60°C) for the wash cycle and 180°F (82°C) for the final rinse. If the temperature is below these levels, the machine cannot sanitize dishes effectively, and you may be out of compliance with health codes. If temperature is low, check the water heater settings and contact a service technician if the problem persists.

Addressing Odors and Discoloration

If your CMA dishmachine develops a sour or musty smell, bacteria and mold are growing inside. This usually happens when the machine sits idle for extended periods or when moisture is trapped in the tank or door seals. Run a hot wash cycle with 2 to 3 cups of white vinegar in the wash tank and no dishes. The acid cuts through biofilm and kills odor-causing bacteria. Follow with two rinse cycles using clean water only.

For stubborn odors, repeat the vinegar cycle and then run a second cycle with a commercial dishwasher cleaner. Leave the door open between cycles to allow air circulation. If the smell returns within a few days, the problem may be in the drain line or sump area. Check that the drain is flowing freely and not clogged with grease or debris. If you cannot clear it, contact a service technician—a blocked drain can cause water to back up and create a breeding ground for bacteria.

Discoloration on the interior surfaces—usually brown, orange, or white spots—indicates mineral deposits or rust. White spots are typically hard water minerals; brown or orange spots suggest rust from the stainless steel or iron in the water. For mineral deposits, use the monthly descaling process. For rust spots, scrub gently with a soft cloth and a commercial stainless steel cleaner, then rinse thoroughly. If rust spots return quickly or spread, the stainless steel may be corroding, and you should have a technician inspect the tank.

When to Call a Service Technician

Some problems require professional service. If the machine does not reach the correct water temperature after you have checked the water heater settings, the heating element may be failing. If water leaks from the door seal or bottom of the machine during operation, the gasket may need replacement or the pump may be damaged. If the spray arms do not rotate or spray weakly even after you have cleared the holes, the pump or motor may need service.

If the machine makes unusual noises—grinding, squealing, or rattling—do not ignore it. These sounds often signal a failing motor, pump, or bearing. Continuing to run the machine can cause more damage and lead to a breakdown during a busy service period. Contact your CMA service representative or a may have access to commercial dishwasher technician to diagnose the problem.

Keep a maintenance log. Record the date of each cleaning task, any issues you notice, and any service calls. This log helps you spot patterns—for example, if you need descaling more often than monthly, your water may be harder than average and you may need to adjust your cleaning schedule. It also provides documentation for health inspections and helps technicians understand the machine's history if repairs are needed.

Frequently Asked Questions

How often should I replace the spray arms on my CMA dishmachine?

Spray arms typically last three to five years with regular cleaning and maintenance. If you notice cracks in the plastic, holes that cannot be cleared, or reduced spray pressure even after deep cleaning, replacement is due. Contact your CMA distributor or service technician for the correct replacement part for your model.

Can I use regular dishwasher detergent in a commercial CMA machine?

No. Commercial dishwashers require detergent formulated for high-temperature, high-volume washing. Regular home dishwasher detergent creates excessive suds, which reduces wash quality and can damage the pump. Use only detergent recommended by CMA for your machine model. Your distributor can advise on the correct product and concentration.

What should I do if my CMA machine leaves spots or film on dishes?

Spots usually indicate hard water minerals or insufficient rinse aid. Check that rinse aid is filled to the proper level and that the dispenser is working. Run a descaling cycle to remove mineral buildup from the spray system. If spots persist, test the water temperature and pressure. Low temperature or pressure reduces wash and rinse effectiveness. If all settings are correct, contact a technician to check the rinse aid dispenser mechanism.

Is it safe to run my CMA dishmachine overnight or over a weekend?

Most commercial dishwashers are designed for intermittent use during operating hours, not continuous or overnight operation. Running the machine when it is not needed wastes water and energy and can accelerate wear on the pump and motor. If you need to run it overnight, check the manufacturer's guidelines for your specific model. Always leave the door open after the final cycle to allow the interior to dry and prevent mold growth.

How do I know if my water pressure is too low for the CMA to work properly?

Low water pressure reduces spray force, which means dishes do not get clean and the machine cannot rinse effectively. Most CMA machines require 20 to 80 PSI (pounds per square inch) depending on the model. If you suspect low pressure, contact a plumber to test your facility's water pressure. If pressure is low, you may need to install a pressure tank or have your water line inspected for leaks or blockages.