How To Fix Your Commercial Dishwasher?

A commercial dishwasher is used continuously during busy hours for ensuring clean and sanitized dishes. If the appliance shows problems, it can affect the workflow of your commercial kitchen. Your best option is to call in a commercial dishwasher repairs expert to inspect the unit and perform repairs, however, you can try some fixes yourself. Let’s look into some commercial dishwasher problems and their fixes.

Fixing A Commercial Dishwasher

Leaking Commercial Dishwasher

Door Seals

The doors of dishwashers also have seals. This is common in many appliances to seal air and moisture. In commercial dishwashers, a seal is to prevent water from escaping the unit. With usage, these rubber gaskets or seals become hard. When they do, they can’t keep water inside the appliance. In turn, water leaks out of the dishwasher during wash cycles.

So, inspect the seals of the dishwasher. If they are not soft or are damaged, consider a replacement. They should be replaced by a professional.

Water Inlet Valve

This is the valve that supplies water to your commercial dishwasher. Any problems with it will obviously lead to water leakage. You will notice a pooling of water near the appliance. So, check that the valve is fit and not loose. Then, look for cracks or damages on the external housing. Then move to the connecting hoses. They should be secured well. If the issue is anything other than a loosely fitted valve, consider a replacement of the inlet valve.


These are seals applied to the joints to make them watertight and airtight. Rubber and silicone O-rings are common. Both of these types deteriorate with time. The elasticity diminishes and the seals no longer remain effective.

They are used in various parts of a commercial dishwasher like the tap fittings, float valves, drains pump, rinse pump, and others.

You will need to check these components of the dishwasher to determine which O’rings are broken so you can replace them. This should be done by a professional.

The Commercial Dishwasher Not Draining

Drain Pump

If your commercial dishwasher is not draining water, the first part to check is the drain pump because it drains water from the appliance. Look for blockages in the pump. Moreover, check the pump for collapsed bearings. A sign of collapsed bearings is a noisy dishwasher. Lastly, the drain pump itself may be faulty.

After checking the above things, you should know that other components also impact the functioning of the drain pump. A control board failure won’t signal the drain pump to drain water, so check the control board, select switch, timer switch, and inlet valve as well.

Drain Impeller

Impellers in a commercial dishwasher create a sucking force for spraying water or other solutions on the dishes or draining the water. A spray impeller sprays water while a drain impeller drains water. If your commercial dishwasher is not draining water, check the drain impeller.

A drain impeller wears with age and can be damaged if any object comes in contact with it. A professional can determine if the drain impeller is fine or needs to be replaced.

Rinse Pump

If you checked the drain pump and it was fine or it was clogged or faulty and you replaced it, but your commercial dishwasher is still not draining, check the rinse pump. It can also wear over time and fail.

So, look for signs that indicate you need to replace the rinse pump. The first is that your dishwasher won’t drain properly. The second sign to look for is noises coming out of the pump during the end of a wash cycle.

The Commercial Dishwasher Is Not Filling

Water Inlet Valve

A water inlet valve has a filter that removes various kinds of particles from water. Once it becomes clogged with particles, the dishwasher will take more time for filling or won’t fill. This filter is easy to access so check the filter and clean it.

Float Switch

Typically, it should move freely. However, if it sustains damage due to age or any foreign objects, it can stop the water from flowing. So, the dishwasher won’t fill.

Timer Control

It controls various components of your dishwasher. Whether your commercial dishwasher is not draining or stops filling, it won’t start or is showing other issues, don’t forget to check the time control and make sure it’s functioning properly. Hire an expert who can replace it.

The Commercial Dishwasher Won’t Start

Power Check

Check if your appliance is plugged in. You should also check the circuit breaker if it’s not tripped. These actions should ensure that your control panel receives power.

If your control panel has power and the dishwasher is still not starting, you should check the doors.

The Doors

The doors of a commercial dishwasher have relays that signal the machine to start. If the door is not closed, the dishwasher won’t start. This is why the dishwasher starts functioning when you close the door.

However, if you shut the door properly and the dishwasher is not starting, the relays connected to the door may be malfunctioning. They are not signaling the control board that the door is shut and begin the operation. So, replace the relays.

Motor Relay And The Motor

The motor relay is responsible for turning the drive motor on and off. So, any malfunction with this relay will result in the drive motor not turning on. Therefore, the dishwasher won’t start.

However, if all the relays are functional, then the drive motor itself can be faulty. This should be checked by a skilled dishwasher expert.

Wet Dishes

Overloading Or Poor Stacking Of The Dishwasher

Dishes are dried by the circulation of air. An overloaded dishwasher will have dishes stacked too near that won’t have enough space for air circulation. So, they will come out wet after the wash cycle. Moreover, improper stacking of the washer will also give similar results.


The thermostat in a commercial dishwasher regulates the temperature of the water that is used for rinsing the dishes. It tells the heating element how much to heat and when to turn it off. If the thermostat is faulty, the water will either not heat or overheat.

Heating Element

Heating elements heat the water to the temperature you set using the control panel. These instructions are sent to the thermostat and it signals the heating element to heat the water and reach the right temperature.

If your thermostat is fine, then the heating elements could be malfunctioning. The heating element should be checked by a professional to know if it’s faulty.

However, there is a sign that can show you when to give attention to the heating element as well along with the thermostat.

If your commercial dishwasher overheats water, it can be a thermostat issue because the heating elements are still heating the water. But if the water isn’t heated at all, it can be either the thermostat or the heating element. So, check the heating element only when the water is not heating at all.


A commercial dishwasher can run into many kinds of problems, so you and your team should know some tips to fix the unit. But if the cause of the issue can’t be determined or you want to fix the appliance quickly, call in a commercial appliances repair Alexandria technician.