Commercial Dishwashers and Warewashing Buying Guide

Selecting the right commercial dishwasher for business operations can be a daunting task. It’s a high-involvement purchase decision that can have a direct impact on production. Several considerations must be made prior to purchasing to ensure the unit will provide the best solutions to specific needs.

Here, we outline the most common dishwasher types, differences between high and low temperature units, a guide to energy efficiency and booster heaters, and provide some general maintenance tips to help units last longer so you can get the most bang for your buck.


Commercial Dish Machine Types

What size and style will fit your facility? When choosing a dishwasher, first determine what type and capacity your facility requires. Dishwashers are rated by the number of dishes or racks they can effectively wash in an hour. For reference, a dish rack can hold approximately 20 dishes. Anticipate the number of meals served a day, the number of dishes used per guest, and the frequency of table turns.

Here are the four main types of commercial dishwashers:

Conveyor Dishwasher

Commercial conveyor dish machines are the largest and most powerful of the dishwashing types, able to run through 350 to 1000 racks a day, depending on size. A 44” conveyor unit, for example, can crank out up to 235 racks an hour.  Conveyor dishwashers work by lining dirty racks at one end of the belt, and they journey through a complete warewashing process, coming out clean at the other end. You can line up several racks at a time for efficient cleaning. These heavy-duty machines are ideal for high traffic commercial locations like cafeterias and hospitals. Due to their size and power, a trained electrician should hard-wire them.

Flight type dish machines are hybrids of the conveyor type, and easily the largest style of dish machine on the market. They use a conveyor belt to push dirty dishes through the cleaning process, but do not require a dish rack like traditional conveyor models. Dishes are placed directly on the belt and venture through different zones to ensure a comprehensive clean and sanitation. Due to their size and power, these machines need to be custom designed for commercial applications and are ideal for large universities or institutions, hospitals, hotels, banquet halls, etc.

Undercounter Dishwasher and Glasswasher Units

Compact is the name of the game for undercounter dish machine units. Undercounter dishwashers are perfect for bars, sliding nicely underneath taking up limited space and enhancing convenience by quickly washing dirty glassware and bar supplies to keep the momentum going during high volume rushes. Commercial glasswashers can typically pump out around 15 racks per hour, making it easy to keep a steady supply of drinkware on hand.

Door Type Dishwasher

Door Type dish machines are much more compact than conveyor machines, squeezing into tighter places. You’ll still need room to set racks for loading and unloading, but space conservation is built into the design by providing connection abilities to clean or dirty dishtables.

There’s no belt that drags racks through from beginning to end. Rather, users fill up a dish rack, push it inside, close the door and run the cycle. These units quickly clean and when the cycle finishes, open the door and unload. Commercial door type machines can typically run 30 to 350 racks per day. These are great for localized, mom-and-pop style operations.


High Temperature vs. Low Temperature (Chemical Sanitizing)

When commercial dish machines are advertised as High Temperature or Low Temperature, this simply refers to the method in which the unit sanitizes its contents. Both high and low temp machines have their benefits.

High Temperature Machines

High temperature machines use heat to sanitize dishes, glassware and flatware. Using a booster heater, the temperature rises to 180°F, effectively killing germs and tackling hard to clean grease and other residues. Due to the high temperature, drying also takes place quickly, eliminating excess moisture and thus preventing bacteria growth.

Low Temperature Dish Machines

Low temperature dish machines, on the other hand, use a sanitizing chemical agent to ensure contents are fully clean and ready for use. These machines only rise to 120 – 140 degrees Fahrenheit instead of the 180° of high temp units, employing the chemicals during the final rinse. Traditionally, these units can save on energy and have lower upfront costs, but the operator will need to continue to purchase chemicals, usually on a monthly basis. Some criticisms of low temperature machines include not drying as effectively as high temp units, which can lead to potential bacteria growth and food safety concerns.

Energy Efficiency

With energy and water costs rising, choosing the most energy efficient unit can have a big impact on overall energy use. Dishwashers can consume up to one-third of an operations energy use, primarily due to the cost to raise water temperature. These machines are rated on water efficiency by gallons of water used per rack. Choosing a machine with lower water usage will help the operator increase efficiency.

Some tips to save energy:

  • Turn the machine off at night
  • Replace torn wash curtains and worn spray heads
  • Repair leaks
  • Verify whether the machine is ENERGY STAR® rated

Booster Heaters

Booster heaters are a type of water heater used to raise the temperature of rinse water to properly sanitize. These heaters are typically built-in to high temperature units and help to ensure the water temperature reaches 180°F. Built-in booster heaters are certainly an advantage to the unit and operator since they’re pre-plumbed, wired and sized for that specific machine. They average around 9kW of power.

There are some machines, however, that only offer booster heaters as an option. You’ll need to make sure to have one in order to ensure the water reaches the correct temperature. If the water comes in preheated, it’s important to double check that the heater can handle the 40°F rise. If the water comes in from a cold tap, the booster heater will need to be able to handle a 70°F rise.

Benefits of booster heaters include rapid self-drying due to higher temperatures that allow excess moisture to evaporate quicker, ensure temperatures are high enough to meet sanitation codes, and they’re usually compact enough to fit right next to your unit.

Commercial water heaters can be purchased independent of dish machines here.

Dishwasher Maintenance

As noted, purchasing a commercial dish machine unit is a high-involvement decision that, depending on the machine, can cost a pretty penny. Here are some suggestions for regular maintenance that can help enhance the life of your machine.

  • Scrape and rinse dishes well prior to running through your dish machine. It can be challenging to remember to do this at times, especially during busy rushes, but this step can enhance the longevity of the dishwasher and make for a more effective clean.
  • Check the vital levels and clean the machine daily, removing all food particles and debris beforehand. Then follow the manufacturer’s directions available in the instruction manual. After cleaning, leave the door open to let it air dry. This reduces the risk of bacteria growth due to moisture buildup.
  • Use thermometer strips to check the water temperature to ensure it’s high enough to properly sanitize. Inadequate temperatures can put your guests at risk of foodborne illness and your operation at risk of a health code violation.
  • Get it inspected annually by a certified technician. This is a great way to fix minor issues and diagnose potential issues, enhancing its lifespan and ensuring it doesn’t break unexpectedly.

Renting vs. Buying a Commercial Dishwashing Unit

It is recommended that you buy your commercial warewasher, but they’re not necessarily the cheapest piece of commercial kitchen equipment. Therefore, renting may seem appealing. However, consider the long-term ramifications.

For starters, leasing commercial equipment usually requires insurance to cover the entire replacement costs, leading to higher insurance premiums. You’re also under contract, and therefore tying yourself to the company for chemicals and service, meaning you’ll be paying their prices and sacrifice the leisure to shop competitively. You lose all room for negotiation.

As we’ve already stated, commercial warewashing units also use a lot of energy and water. Therefore, you can save money by purchasing an energy-efficient model. However, because using more water means buying more chemicals, rental companies rarely offer these models. This also prevents your from taking advantage of certain incentives, like rebates for ENERGY STAR® certified equipment, and tax benefits like the Section 179 deduction that allows businesses to deduct equipment costs and can earn you up to $500,000 back on your total equipment purchases.

Another important consideration – and be forewarned, it’s not one many businesses enjoy thinking about – is the possibility of going out of business. It’s an unfortunate reality, and you could be looking at high penalties or buyouts if you’re under contract with a rental company. If you own your dishwasher, you can recover some of the cost by selling it to another foodservice operation or an equipment dealer.


Top Dishwashing Manufacturers

Here are a few of the top manufacturers in commercial dishwashing. Click the links to view and compare their assortments. If you would like more information, please call 800.215.9293 to speak with one of our knowledgeable product experts to help you find the best fit for your needs.