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5 Most Common Mistakes in Your Warewashing Program & How to Fix Them

5 Most Common Mistakes in Your Warewashing Program & How to Fix Them

If you’ve spent any time running a warewash program, then chances are you’ve experienced at least one of its many hardships, like spotty wares, clogged machines, equipment downtime, or  customer complaints among other things

Typically, these problems are the result of ONE common mistake. Yes, you read that right. Just one wrong misstep in your warewash program can be causing all those issues – from spotty wares to broken equipment. 

The most frequently performed mistake is that staff don’t adequately scrape and pre-rinse their dishes before loading them into a dishwasher. 

If a dish is still covered in food particles when it enters the dishwasher, those food particles can wreak havoc on the machine’s internal processes.

Aside from failing to properly clean the dishes, the most common mistake, there are also other mishaps that can lead to a poorly performing warewash program. 

For this article, we’ve identified the five most common warewashing mistakes, and how to fix them so you can reduce the frequency of equipment downtime and customer complaints while focusing on more important issues.

Top 5 Warewashing Mistakes

  1. Poorly Scraping and Pre-Rinsing Dishes 
  2. Loading the Dishwasher Incorrectly
  3. Failing to Check the Dishwasher Temperature and Pressure
  4. Disregarding Daily Cleaning Procedures
  5. Neglecting to Routinely Delime the Dishwasher

#1 Poorly Scraping and Pre-Rinsing Dishes

Failure to pre-scrape and rinse dishes is the most commonly made warewashing mistake. In fact, almost all dish machine malfunctions can be avoided if the workers in your warewashing program scrape and pre-rinse dishes before putting them into the dishwasher

If your staff doesn’t scrape and pre-rinse dishes before loading them into a dishwasher, expect an excess of food debris inside of the machine. When there is a lot of food debris in the machine, any number of things can go wrong. 

The first thing that happens is that the spray nozzles, pump screen, and any drains become clogged. Because of this, the water in the machine will get dirtier and dirtier as food particles are pumped throughout. Food particles will then get deposited on dishes, requiring them to be recleaned. 

The dishwasher will then sense that it is more dirty on the inside than it’s supposed to be and will pump more chemicals into the water as a countermeasure. As a result the machine ends up costing you more on wasted product. 

To avoid dealing with a clogged dish machine,spotty wares, and rewashing always fully scrape and pre-rinse dishes before loading them. 

#2 Loading the Dishwasher Incorrectly

Overlapping or overcrowding dishes onto a tray can prevent water from reaching all of the surfaces. Proper loading techniques are required to ensure that the water reaches every dish surface. 

Without following proper technique, dishes will not get cleaned. If a dish is blocking another dish from getting washed, it is referred to as shielding. Shielding prevents dishes from getting properly rinsed, requiring them to be run through the machine again. 

It can also cause damage to internal components. If improperly loaded, smaller dishware, like cutlery, can be shot off the rack by spray pressure and get caught in the pump impeller. When internal components are damaged you can expect significant equipment downtime while waiting for repairs or replacement parts. 

This mistake, like many of the others that we cover, has a simple solution: load the dishwasher in accordance with proper guidelines. 

Let’s briefly review some dish loading guidelines:

  1. Glasses, cups, and bowls should be turned upside down
  2. Plates and flatware should be stood up edgewise
  3. Stack dishes in the dish racks (do not stack them on top of each other)

#3 Failing to Check and/or Properly Calibrate the Dishwasher Temperature and Pressure

Your service technician should have calibrated the dishwasher’s temperature and pressure settings the last time they serviced the machine. However, if there is a problem with the dishwasher, it may not function properly. This is why it’s important to check the gauges every time the machine gets used.  

Without checking the dishwasher temperature and pressure gauges, you cannot confirm if the machine is running at the right temperature, or if the pressure is at an acceptable range. If either of these functions are not running within the correct range, then your dishwasher will not work properly, and efficient warewashing will prove impossible.

If the dishwasher temperature is not correct, then the machine will not be able to properly clean dishes or satisfy health codes. Similarly, if the pressure is too low, then you will not get proper rinsing or coverage, or if the pressure is too high, your rinse agent may not inject into the machine because the rinse pump can’t overcome the high pressure, which will result in water spots on your wares and extended dry times. 

The best temperature to set your dishwasher to is dependent on whether it is a heat-sanitizing (high-temp) or chemical-sanitizing (low-temp) unit. One way to tell whether your machine is a high-temp or a low-temp unit is based on their minimum required temperatures for rinsing and washing. 

For high-temp dishwashers, your unit should show a minimum rinse temperature of 180F, and a minimum wash temperature of 150F to 160F (depending on the make and model). For low-temp dishwashers, the machine should show a minimum temperature of 120F for both rinse and wash. 

Regardless of whether your dishwasher is high-temp or low-temp, the pressure range stays the same. You want the dishwasher rinse pressure to read between 15-25 PSI. Anything outside of this range will negatively affect how your machine is able to rinse dishes. 

There is no easy solution if you’re unable to meet the minimum required dishwasher temperature and pressure. The only safe alternative for cleaning dishes is to hand wash and sanitize your wares using the 3-sink method.

All you can do is double check the machine’s gauges immediately after you begin use, each time. You can run a couple of empty racks to see if your dishwasher temperature rises, but if it doesn’t, your only solution is to call a mechanic for immediate servicing. 

#4 Disregarding Daily Cleaning Procedures

Your dishwasher may just be the most important piece of equipment in your warewashing program, so it’s vital that the dishwasher is well maintained. Typically, that requires daily cleanings. 

Frequently, you’ll find that the dishwasher’s internal components are not thoroughly maintained on a daily basis. Some staff may think that because it wasn’t a high traffic day or because the dishes weren’t that dirty then one or more cleaning procedures can be ignored. 

Don’t let them make this mistake. Because this is such an important task, and there are varying consequences depending on what is and isn’t cleaned, we’re going to look at three daily dishwasher cleaning procedures that people in warewashing often overlook.

  1. Drain and Clean the Water Tank After Each Shift 

When dirty water builds up in the tank, it causes some nasty issues, such as bacterial growth. So, after each meal shift, drain and clean the wash tank. This effectively prevents the buildup of food particles and ensures that the water does not get dirty, so you don’t have to worry about any odor buildup or water level issues.

  1. Always Clean the Wash Arms, Rinse Arms, and Pump Screen

Over time, it’s natural for internal components to become blocked or clogged. This often happens with the wash arms, rinse arms, and pump screen. The solution is to remove the pump screen, rinse arms, and wash arms after each meal shift so that they can be thoroughly cleaned. By cleaning these components multiple times a day, you ensure that nothing stays clogged, allowing the water pressure to stay high and the spray jets to do their job. 

  1. Let the Dishwasher Air Dry at the End of the Day

If the dishwasher isn’t dried at the end of the day, or allowed to air dry, it will remain wet overnight. A moist environment like the inside of a dishwasher has the perfect atmosphere to promote bacterial growth. To avoid this, leave the doors to the dishwater propped open so that it can air dry overnight. 


#5 Neglecting to Routinely Delime the Dishwasher

When left unchecked, limescale or mineral buildup occurs on the walls, in the rinse arms, and on the heating elements of the dishwasher. Failure to routinely delime a dishwasher can have 

some serious problems with the machine’s ability to operate and effectively clean dishes. 

When coated with limescale, internal components like the heating elements cannot effectively do their job and will prematurely wear out. If the heating elements wear out, they can longer heat the water up to proper temperatures. Without adequate levels of heat, dishes are not getting cleaned or sanitized. 

If the heating elements become worn out, they need to be replaced sooner than they should have been. This ends up costing you money on replacement parts, repairs, and equipment downtime. 

Similarly, limescale will clog up internal components, like the rinse jets. When clogged, they’re unable to properly rinse and sanitize your wares. These jets will not be able to produce an even spray pattern. This results in the wares not being properly rinsed and sanitized. 

The solution here is to break down the limescale build up that you’re experiencing with delimer. You can do this anywhere from bi-weekly to once a month, depending on whether your warewash operation is in a hard water area. 

You can always be cautious and delime bi-weekly regardless of water quality. Regularly deliming will reduce your water and energy usage dramatically, as it improves the performance of the machine. 

Final Thoughts

Running a warewashing program is hard enough without having to deal with customer complaints and equipment downtime. 

We gave you five of the most common warewashing mistakes, see how many of them you can identify in your operation. If you run into any of them, refer back to this article for the fix. 

If you find yourself in need of a program overhaul, reach out to us today!

At Imperial Dade, we offer a full line of superior products, quality control testing, innovative dispensing systems, and unparalleled service & training to help you achieve maximum operational efficiency in your warewashing program.

Contact us for a free onsite or virtual evaluation, where we’ll have a specialist work with you to develop the most effective warewashing program for your operation. 

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