Commercial Dishwasher Troubleshooting and Maintenance Guide
A reliable commercial dishwasher is one of the most important pieces of equipment in any restaurant, hotel, bar, bakery, cafeteria, or catering kitchen. When it stops working, won’t start, isn’t heating, or isn’t draining properly, it can interrupt your entire operation and cost time and money.
Many common commercial dishwasher issues can be handled with basic troubleshooting. This guide covers what to check when your dishwasher isn’t working and offers commercial dishwasher maintenance tips to help you keep it running efficiently and avoid breakdowns.

Common Commercial Dishwasher Problems
If your commercial kitchen’s dishwasher isn’t starting, heating, draining, or completing its cycle, there are a few common issues to check before calling for repairs.
Commercial Dishwasher Leaking Water
If your commercial dishwasher is leaking water, it can lead to serious issues like floor damage, equipment wear, or even safety hazards in a busy kitchen. In most cases, leaks come from cracked hoses, loose pipe fittings, or worn door seals. Over time, limescale buildup in the rinse or boiler tanks can also lead to rust, which may cause slow leaks or other performance problems.
To help prevent leaks, it’s important to clean the dishwasher daily and check the water lines and seals for any signs of wear. You can also use a water softener or descaler to reduce limescale buildup and keep your machine running smoothly.
If you’re also noticing water pooling at the bottom of the unit, check out these tips for fixing standing water in a commercial dishwasher.
Commercial Dishwasher Not Starting
If your commercial dishwasher won’t start, the issue might be something simple or a sign of a larger electrical or mechanical problem. Start with the basics: first, check to make sure the unit is plugged in and the breaker hasn’t tripped. Once you’ve ruled out a power issue, here are a few other things to look at:
Common Reasons a Commercial Dishwasher Won’t Start
Here are some of the most common reasons your commercial dishwasher won’t start:
- Faulty Door Switch or Selector Switch: If the door switch or selector switch is malfunctioning, the control board won’t receive the signal to start the wash cycle. Make sure the door is fully closed and the latch engages properly.
- Drive Motor or Motor Relay Problem: The motor relay sends power to the dishwasher motor. If the relay is working but the unit still doesn’t start, the issue may be with the drive motor itself. A damaged or non-functioning motor will stop the machine from running.
- Control Board or Timer Failure: The control board and timer manage power distribution and cycle timing. If either component is faulty, the dishwasher may not turn on or respond to cycle settings.
Commercial Dishwasher Won’t Drain
If your commercial dishwasher isn’t draining properly, the first thing to check is the dishwasher filter. Food debris and grease can easily clog the filter and block water from flowing out. Remove the filter cage, clean it thoroughly, and replace it securely.
If the machine is still backed up, the issue may be in the drain hose or internal pipes. These can become clogged with buildup over time. In most cases, you can clear the blockage yourself with basic tools and a careful inspection.
For more detailed steps, check out this guide on why your commercial dishwasher isn’t draining. If your dishwasher still won’t drain, it may be time for a professional repair. Contact Quick Servant for fast and reliable commercial dishwasher service.
Commercial Dishwasher Not Cleaning Dishes Properly
If your dishwasher is starting and it appears to work, but the dishes it’s supposed to be cleaning aren’t coming out nice and clean, there could be a few reasons why this is happening. It could be old or poor quality detergent that’s being used, a problem with the water not heating up, or an issue with not enough water filling up the dishwasher. In these instances, check the inlet valve and floating wave as they may be the problem. Buy some good quality detergent as well!
If your dishwasher is running but the dishes aren’t coming out clean, there are a few possible reasons. You might be using low-quality detergent, or the water may not be heating properly. Another common issue is low water levels, which can be caused by a faulty inlet valve or float switch.
Make sure you’re using a high-quality commercial dishwasher detergent and check the spray arms for clogs. Also, confirm that the water is reaching the correct temperature for proper sanitizing.
There are many reasons a commercial dishwasher may stop working or underperform. While some issues can be fixed with basic troubleshooting, others may require professional service.
If your dishwasher still isn’t cleaning dishes properly, contact Quick Servant or call 888-238-4133 to schedule a service visit. Our team provides fast and reliable restaurant dishwasher repair to get your equipment back in service quickly.