Commercial Dishwasher Repairs: Common Problems, Causes & What to Do Next
If your commercial dishwasher stops working mid-service, the impact can be immediate and costly. Hygiene, efficiency, and customer experience all suffer when you’re forced to handwash dishes during busy hours. Whether you operate a restaurant, café, hotel, or school kitchen, knowing what causes breakdowns and how to handle commercial dishwasher repairs quickly is key to keeping operations smooth. We work with all types of manufacturers from spasres for Winterhalter, to Classeq and Hobart Dishwasher Parts (and further afield).
This guide covers the most common commercial dishwasher faults, their potential causes, and what steps to take next to minimise downtime.
Why Commercial Dishwashers Break Down
Heavy daily use, high water temperatures, hard water scale, and food debris all put strain on commercial dishwashers. Most units run through hundreds of cycles per week, so even a minor issue can turn into a major disruption without fast attention.
Failing to carry out routine cleaning, descaling, and maintenance also increases the risk of breakdowns.
Most Common Commercial Dishwasher Problems
1. Dishwasher Not Heating Properly
Symptoms: Dishes not sanitised, cold final rinse, error codes.
Possible Causes:
Faulty heating element or thermostat
Limescale buildup on the element
Faulty wash tank temperature sensor
If your model fails to reach the correct sanitising temperature, it may not be compliant with food hygiene standards—this requires immediate attention.
2. Poor Cleaning Results
Symptoms: Dirty dishes, streaks, grease residue, cloudy glasses.
Possible Causes:
Blocked or clogged spray arms
Detergent not dispensing correctly
Incorrect detergent type or water hardness imbalance
Worn or cracked wash/rinse arms
Always check filters and spray jets first, and ensure you’re using commercial-grade chemicals suitable for your machine and water type.
3. Dishwasher Not Draining
Symptoms: Standing water in the bottom of the machine, cycles not completing.
Possible Causes:
Blocked drain pump
Clogged filter or food trap
Kinked or blocked drain hose
Blockages are common and can often be resolved with a manual clean, but pump faults may require replacement parts.
4. Water Leaking from Machine
Symptoms: Pools of water on the floor, visible dripping or pooling under the unit.
Possible Causes:
Perished door seals or gaskets
Cracked internal pipe or drain valve
Overfilling caused by a faulty inlet valve
Leaks can be a health and safety risk—especially in high-footfall kitchens—so shut down the unit and isolate power if leakage is severe.
5. Machine Not Filling with Water
Symptoms: Won’t start cycle, low water pressure warning.
Possible Causes:
Blocked inlet valve or solenoid failure
Low incoming water pressure
Faulty float switch or level sensor
Check that taps and isolation valves are fully open before diagnosing internal faults.
6. Error Codes or Beeping
Symptoms: Machine won’t operate, LED or screen displays code.
Possible Causes:
System-specific faults (refer to manufacturer manual)
Issues with sensors, wiring, or control boards
Note the code before switching off the machine—this helps engineers identify the fault more efficiently.
What to Do Next
When your dishwasher stops working, here’s how to respond effectively:
Stop the Machine Safely
Turn off the power and water if there’s a leak or potential electrical fault.Check for Obvious Blockages
Remove filters, inspect spray arms and traps for food debris or limescale.Note Any Error Codes or Symptoms
Take a photo or write down what you see—flashing lights, fault codes, beeping patterns.Check Your Spare Parts
If you keep commercial catering spares on hand, simple fixes like gaskets, filters, or valves can be done quickly in-house.Book a Professional Repair
For electrical, heating, or pump faults, contact a specialist in commercial dishwasher repairs. Many issues can be diagnosed and resolved on-site within a single visit.Schedule Regular Maintenance
Prevention is cheaper than replacement. Arrange commercial kitchen maintenance to keep your dishwasher and other appliances in top condition.
Bonus Tip: Descale Regularly
Hard water is the enemy of dishwashers. Regular descaling using a commercial-grade product extends the life of elements, sensors, and valves. Consider installing a water softener if you’re in a hard water area—it can dramatically reduce breakdowns and service calls.
By acting quickly and knowing what signs to look for, you can avoid extended downtime, poor hygiene ratings, and repair bills that spiral out of control. Keeping a few key commercial catering spares in stock and having a trusted repair service on speed dial ensures your commercial dishwasher stays a reliable part of your kitchen—not a liability.