Commercial Dishwasher Repair, Maintenance, and Parts: The Ultimate Guide

Sanitation and cleanliness should always be a top priority in your commercial kitchen. Now more than ever, it is essential to practice proper sanitizing and washing methods. Dirty tableware can not only alter a customer’s perception of your establishment, but it can also expose them to dangerous foodborne illnesses. It is recommended to flush dish machines after every shift. Doing so will remove accumulated soil from the machine, thus increasing washing performance, and reduces detergent usage. An ounce of preventative maintenance goes a long way to preserve the life of the machine.

What are the Main Components of a Dishwasher?

Inlet Valve: Supplies water to the dishwasher.
• Common Issues: Causes dishwasher to overflow / not fill at all / or fill when the appliance is not in use. If your dishwasher continues to fill once the water level reaches the overflow, try opening the door to see if the water stops filling. If the water continues to fill, you may have a faulty inlet valve that needs to be replaced.

Wash Impeller or Pump Impeller: Most dishwashers have a top and bottom impeller, also called the wash impeller and the drain impeller.
• Common Issues: Can become clogged with food or detergent, causing the spray arms to not dispense water.

Drain Hose: Expels water.
• Common Issues: Dishwasher not draining. Drain hose might be clogged or kinked. Try removing the drain hose to unclog debris and re-route to prevent pinching. If the drain hose is cracked or damaged, consider replacing.

Thermostat: Activates heating elements to maintain proper water temperature.
• Common Issues: A malfunctioning thermostat can cause the heat to shut off before the proper water temperature is reached. Unplug the machine and test the thermostat for continuity with a multi-meter.

Heating Element: Heats water during the wash and rinse cycles.
• Common Issues: Water not reaching temperature. Unplug the machine and test heating elements for continuity with a multi-meter.

Circulation Pump: Uses a motor and impeller to force water up through the wash arms.
• Common Issues: Dishwasher may be noisy and dishes may not be cleaned properly. Check to see if the motor has failed if the pump is not running at all. If the motor is running but not creating enough water pressure through the spray arms, the impeller may be damaged.

Wash Pump Motor: Spins the wash pump impeller.
• Common Issues: Dishwasher may be noisy, dishes will not be properly cleaned and you may notice decreased spray pressure. If the motor has stopped working, it will need to be replaced, along with the water seals. If the motor does not run, the wash pump relay or contactor may be defective.

What’s the Difference between a High Temperature (Heat-Sanitizing) Machine and a Low Temperature (Chemical-Sanitizing) Machine?

• High-Temperature Dishwashers use hot water to sanitize wares, as well as remove visible impurities, and bacteria. According to the NSF (National Sanitation Foundation), a commercial dishwasher (High Temp & Low Temp Machines) must have hot water that is at least 120 degrees in order to properly sanitize wares. A High-Temp dishwasher uses wash water that is between 150-160 degrees and rinse water that is between 180-195 degrees.

• Low-Temperature Dishwashers use chemical sanitizers (ammonium (Quats), chlorine, or iodine) to properly clean and sanitize wares. The water temperature during the wash and rinse cycle is usually between 120-150 degrees. Water temperature should not exceed 150 degrees in a low temp dishwasher, as this causes the cleaning agents to become unstable.

Is a High-Temp Commercial Dishwasher Better Than a Low-Temp Commercial Dishwasher?

It depends on the application. For most commercial kitchens, a high-temp dishwasher seems to be the first choice. Although, that’s not to say a low-temp dishwasher doesn’t have its place. When initial cost is the biggest deciding factor, a low-temp dishwasher is the way to go. A low temp dishwasher uses less energy, therefore it is more cost-efficient in that regard. Some high-temp dishwashers require a booster heater, which heats the water to higher temperatures between 180-195 degrees. When an abundance of steam is created in the kitchen, a condensate hood is usually required, thusly adding secondary costs.

The downsides to a low-temp machine are monthly costs for chemical sanitizers, drying times are extended due to dishes being a lower temperature when washing cycle is complete, additional washing cycles in order to properly remove animal fats, lipstick, etc. and possible damage to certain types of flatware, dinnerware, and plastics.

What are the Most Common Types of Dishwashers?

• Undercounter Dishwashers – Compact units that are commonly used in small operations like diners, bars, cafes, coffee shops, and churches. Typically uses between .5-2 gallons of water per rack.

• Single and Double Rack Dishwashers – Usually installed between dish tables. It can process up to 175 racks per hour and uses about .75-3 gallons of water per rack. Commonly used in small-medium restaurants, corporate facilities, etc.

• Conveyor Dishwashers – Uses a conveyor belt to carry racks through the machine. Processes about 700 per hour and uses about .5-1.2 gallons of water per rack. Commonly used in nursing homes, hotels, large restaurants, etc.

• Flight Dishwashers – This type of machine is custom built to the facility’s needs. Dishes are placed directly on a conveyor belt. Commonly used in prisons, universities, banquet halls, and hospitals.

What Exactly is a Booster Heater?

A typical water heater normally measures between 110 and 150 degrees Fahrenheit. A booster heater comes in 40-degree and 70-degree rise versions which allows you to have proper water temperature (180 degrees Fahrenheit minimum) to use in your high temp dishwasher.

Additionally, hard water can also affect your booster heater’s lifespan. A service technician can help you determine your water hardiness.

How Does Hard Water Affect My Commercial Dishwasher?

One word: limescale. Limescale can cause serious damage to any type of appliance that uses water. Most facilities in New Jersey have hard water due to high levels of calcium and magnesium. Lime buildup causes chalky white deposits to form inside your machine and on dishware and decreases the overall efficiency over time. We have a variety of commercial cleaners and chemicals to combat limescale in your machine, which are often called descalers or delimers.

What Type of Chemicals are Commonly Used in Commercial Dishwashers?

• Detergents – Available in a variety of formulations for both low and high temp dishwashers. Combats impurities and dirt. Liquid and solid detergents are available.

• Rinse Aids – Reduces surface tension of the liquid it’s dissolved in. This helps to remove water spots, which is particularly helpful if your establishment has hard water.

• Sanitizer – Efficiently kills germs and bacteria.

How Can I Extend the Life of My Dishwasher?

1. Regular and routine maintenance is the number one way to prevent premature wear on your dishwasher. Some maintenance can be done in house, but it’s best to leave repairs and certain maintenance tasks to a professional commercial kitchen service company. Our expert technicians are available 24/7 to assist you!
   
2. Choose the proper sized dishwasher for your facility’s needs. Having the proper size dishwasher prevents your employees from overloading the machine. An overloaded machine prevents dishes from getting completely cleaned due to crowding and overlapping.

How Can Service Plus Help?

With over 37 years of experience, we have the knowledge and expertise to help troubleshoot any issue you may have. Below is a brief overview of the services we offer.

Service:

• 24/7 Emergency Service
• Scheduled Maintenance
• Repair

Replacement Parts:

Manufacturers We Work With:

References:
https://www.partselect.com/Repair/Dishwasher/Not-Drying-Properly/
https://caenergywise.com/