How to Clean a Commercial Dishwasher : A Practical Guide for Professional Kitchens.

In most commercial kitchens, the dishwasher rarely gets a second thought until something goes wrong: plates come out greasy, food residues remain, or the machine suddenly refuses to heat properly. Yet with a simple cleaning routine, most of these issues can be prevented. A well-maintained commercial dishwasher uses less energy, lasts longer and delivers consistently better results during busy services.

The guidance in this article applies to commercial dishwashers such as undercounter and passthrough (hood-type) models commonly found in professional kitchens.

Why Regular Cleaning Matters

Throughout every service, a commercial dishwasher handles a constant flow of plates, utensils and containers, all carrying food residues, grease and starch. At the same time, the machine is working with hot water, detergents and, in many areas, hard water that leaves limescale behind.

If deposits are not controlled, the effects soon become noticeable:

Wash results deteriorate, leaving film or residues on crockery

Unpleasant odours develop inside the cabinet

Spray patterns weaken as jets block

Heating times increase and energy use rises

Pumps, elements and seals experience avoidable wear

Regular cleaning is therefore not just about hygiene; it is a basic maintenance routine that protects both performance and the machine itself.

Daily Cleaning Routine

1. Drain the machine

At the end of service, allow the dishwasher to drain completely. This removes dirty wash water, detergent residues and most of the loose food particles that have built up during the day.

2. Clean the filters

Commercial dishwashers have filters designed to protect the pump and maintain water quality. Remove all accessible filters and rinse them under warm running water. Gently remove trapped debris but avoid using abrasive tools that could damage the mesh.

3. Rinse the spray arms

Spray arms can become blocked by seeds, peel, starch and other fine debris. Remove the arms according to the manufacturer’s instructions, rinse them thoroughly and carefully clear any blocked jets. Strong, even spray patterns are essential for reliable cleaning.

4. Wipe the interior

Using warm water and a mild, non-abrasive detergent, wipe down the interior of the wash chamber, the inside of the door and around the door seal. This helps prevent films of grease from forming and keeps odours under control.

5. Reassemble the components

Once everything is clean, refit the filters and spray arms correctly so that the dishwasher is ready for the next shift. Incorrectly fitted parts can significantly affect wash performance.

Weekly Checks

1. Look for scale buildup

White, chalky deposits on tanks, spray arms or internal surfaces indicate limescale. A small amount is normal in hard-water areas, but visible buildup should not be ignored as it affects heating efficiency and water distribution.

2. Clean around the door seals

Food residues and detergent can collect in the folds of the door seal. Wipe this area carefully once a week to maintain a good seal and prevent odours.

3. Inspect chemical dosing lines

Check that detergent and rinse-aid tubes are secure, free from kinks and not obstructed. Consistent chemical dosing is vital for both wash quality and the protection of glass and crockery.

Cleaning vs Descaling – What Is the Difference?

It is important to distinguish between cleaning and descaling, as they tackle different issues inside the dishwasher.

Cleaning focuses on removing grease, food residues and general soil from the chamber, filters, spray arms and door areas. This is the routine described above and should be carried out daily.

Descaling is the process of removing mineral deposits left by hard water. Limescale tends to build up on heating elements, the base of the tank, spray arms and within internal pipework. Over time, this reduces energy efficiency and can lead to component failure.

Both routines are necessary. Cleaning maintains hygiene and day-to-day performance, while periodic descaling helps prevent long-term damage caused by hard water.

Using the Right Cleaning Products

Commercial dishwashers are designed to work with specialist detergents, rinse aids and descaling agents. These products are formulated for high-temperature, low-foam operation and for tackling the types of soil found in professional kitchens.

Household dishwasher cleaners and domestic detergents are not suitable. They may foam excessively, fail to rinse correctly or react poorly with the machine’s dosing and heating systems. In some cases they can also damage seals or finishes.

For best results, operators should use products recommended by their catering equipment supplier or hygiene chemical provider and follow the manufacturer’s instructions carefully, including any guidance on dilution and contact times.

Monthly Deep Clean

In addition to the daily and weekly routines, a more thorough clean should be carried out roughly once a month, or more often in very hard-water areas. This deeper clean should focus on:

Areas beneath and around the filters at the base of the tank

Corners, seams and welds inside the wash chamber

The underside and bearings of spray arms

Any accessible internal surfaces where grease and scale may collect

This is also a good opportunity to confirm that the machine is reaching the correct wash and rinse temperatures and to visually inspect door seals and hinges for wear.

Good Practices for Long-Term Reliability

Use a water softener where required. In hard-water areas, a correctly specified water softener helps prevent rapid limescale buildup and protects internal components.

Scrape plates before washing. Dishwashers are not designed to act as waste disposers. Removing food waste at the sink or prep area will keep filters clear and improve results.

Leave the door ajar after cleaning. Allowing the cabinet to dry helps to prevent condensation, musty smells and microbial growth.

Consider planned servicing. Periodic maintenance by a qualified engineer can identify worn parts early and reduce the risk of unplanned downtime.

Final Thoughts

A commercial dishwasher is a key asset in any professional kitchen, and a few minutes of routine care each day can make a significant difference to its performance and lifespan. By combining regular cleaning, sensible descaling practices and the correct use of specialist detergents, operators can maintain high hygiene standards, minimise running costs and keep service running smoothly.

Need help or unsure about the right cleaning routine for your dishwasher? Our team is always here to advise on best practices, maintenance tips and suitable products for your kitchen’s needs.