Commercial Dishwashers: Your Questions Answered

Anyone who has a dishwasher can scarcely imagine life without one. What’s a useful timesaver at home is an absolute necessity at work if you’re in a commercial kitchen. Yet the commercial dishwashers used in professional kitchens are a step or two above the home varieties—powering through dishes to keep service ticking over.

High performance tends to come with a high price tag, meaning that you want to know you're making the best possible investment when choosing a commercial dishwasher. Below we’ve tried to answer all of the questions you might have about commercial dishwashers to help you through that process: how they work, how best to use them, and what to consider when buying one.

What is a commercial dishwasher?

A commercial dishwasher is a dishwasher specifically designed for commercial kitchens. While domestic dishwashers are designed to be compact and used relatively infrequently, commercial dishwashers are much larger, and are designed to operate almost continuously. 

Commercial dishwashers have extremely high capacities, allowing them to clean and dry large quantities of dishes, cutlery, and other items in a short time frame so that they can be rotated back into service. They are also extremely effective at cleaning, ensuring a high level of cleanliness for customers and maintaining good food hygiene.

Commercial dishwashers come in three main varieties:

Undercounter dishwashers

Commercial undercounter dishwashers are the most similar kind to domestic dishwashers. These dishwashers are compact but still allow for effective cleaning at high speed, with the capacity to clean as many as 500 plates per hour. Where a domestic dishwasher might take 90 minutes or more per cycle, these units can clean dishes in as little as three minutes.

Undercounter dishwashers are extremely compact, making them perfect for small premises, such as behind the bar in a pub or restaurant, or in a small kitchen. Like a home dishwasher, they are typically very easy to load, and tend to be less expensive than other variants of commercial dishwashers, making them a great starting point.

Pass-through dishwashers

Pass-through dishwashers are tall, freestanding commercial dishwashers designed for high-speed and high throughput. Pass-through dishwashers work by sliding a rack of dishes into place at counter level, before pulling the hood of the machine down on top. The machine then cleans the rack of dishes, which can be slid out of the other side and dried ready for use.

Pass-through dishwashers can clean as many as 1200 dishes per hour, and are extremely ergonomic for most people to use, as they do not require you to bend down to load the dishwasher. However, they are slightly pricier and much larger than undercounter dishwashers, requiring tables either side of the dishwasher to roll the dishes in and out, and optionally to rinse them before washing. They may also be difficult to use for smaller staff, who may have trouble lifting and closing the dishwasher hood.

Conveyor dishwashers

Conveyor dishwashers provide a highly automated and rapid level of cleaning. Functioning much like the X-ray scanners at airports, conveyor dishwashers work by sliding a rack of dishes into one end on a conveyor belt, which is then washed and deposited on the other end. This allows for almost no downtime, with dishes being quickly deposited and collected when clean.

Conveyor dishwashers are extremely efficient, cleaning as many as 2300 plates per hour. The length of the dishwasher naturally means that it requires a large amount of space, and you may also wish to add a dishwasher table for pre-rinsing. However, they can also have the added benefit of a drying chamber, allowing dishes to be put directly back into use.

How often should you clean a commercial dishwasher?

Commercial dishwashers should generally receive a light clean every day, and a deep clean every week, or every month at a minimum. This ensures that both the service life of the machine is maximised, and that it continues to operate in an effective and hygienic manner.

The daily clean should involve removing any food debris from the interior of the machine, with a particular focus on the filter and dishwasher arms. The surfaces should also be cleaned with a brush and warm water or an appropriate surface cleaner, along with the seals and other harder-to-reach areas.

The weekly or monthly deep clean should involve carefully cleaning all of the detachable components of the dishwasher, including the dishwasher arms, filters, and nozzles. It should also involve thorough cleaning of seals and gaskets, and topping up the dishwasher salts and rinse aid if required.

Note that the precise cleaning schedule for a commercial dishwasher will vary depending on how often it is being used, the food that is being cleaned, whether you are in a hard water area, and the precise requirements of the dishwasher. The dishwasher manual or manufacturer’s website will be able to provide more detailed information on proper maintenance procedures.

What temperature do commercial dishwashers reach?

The rinse temperature of a typical commercial dishwasher can reach up to 82°C, or around 180°F. The recommended water temperature to kill bacteria is above 70°C, meaning that commercial dishwashers will both effectively sterilise dishes and cutlery, and allow for efficient and proficient cleaning.

Why are commercial dishwashers so fast?

A big part of the reason for investing in a commercial dishwasher is how fast they are. Being able to wash (and dry) dishes and cutlery so quickly is imperative for being able to turn them around quickly for use by customers. Without this, large restaurants would need an enormous surplus of cutlery to ensure that everyone is able to eat simultaneously when needed.

Commercial dishwashers operate much faster than domestic dishwashers for several reasons. For one, the water is very quickly heated to extremely high temperatures using a tank or booster heater. Commercial dishwashers also tend to operate at higher pressures than domestic variants, ensuring all items are thoroughly cleaned.

As well as being combined with a significant amount of detergent, plates and other items that are being cleaned have only just been used, preventing food from drying onto them. Any potentially tricky items also tend to be rinsed at a dedicated station before being washed, ensuring that items do not require a long time to properly clean.

How to choose a commercial dishwasher

The biggest factor when choosing a commercial dishwasher is likely to be how many dishes you need to wash. As well as the size of your establishment and how much space you have, the required throughput is likely to be crucial when choosing a dishwasher. 

If you need to heavily supplement the dishwasher because it doesn’t wash enough dishes, then this use of additional space and manpower will mitigate the benefits of owning one. Likewise, investing in a commercial dishwasher that’s too big will limit what else you can use the space for, and lead to additional initial, running and maintenance costs that will outweigh the benefits.

Consider where the dishwasher will be placed, and the ergonomics of using it for staff. You will also want to look at the running costs, including the energy efficiency of the dishwasher, the cost of detergent and rinse aid, and how effectively it recycles water, as well as the cost of any water filters.

It’s also worth researching the reliability of different dishwashers, and their potential maintenance costs. This is an area where it can be beneficial talking to other contacts you may have in the industry, or to specialist suppliers who sell, fit and maintain the machines themselves, giving you an idea of which brands you can trust.

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At Commercial Catering Contracts, we have more than 30 years’ experience in supplying and fitting a range of commercial dishwashers, as well as glasswashers, spray guns, and other related equipment. To learn more about what we offer and the leading manufacturers we work with, don’t hesitate to get in touch with us today.