Is your facility fighting COVID-19 with proper hygiene?  Click here to find out more

How Much Does Commercial Dishwasher Descaling Cost?

Commercial dishwashing descaling cost
How often is your hygiene equipment serviced? 

From dishwashers to washing machines, your equipment is vital to your ongoing hygiene. Failure can lead to a lower quality of life for your residents, and increased costs to your facility. 

So, how much does failure cost? 

And how much does it cost to prevent? 

We’ll look at a specific example for this case study – scale build-up in dishwashers. 

The Total Cost of Hygiene Consumables   

Did you see our other posts in this series? We’ve got articles on chemicals, hand soap, vinyl gloves, toilet paper and surface sanitiser

If not, here’s a quick rundown on our concept.    

Our research in residential aged care has shown us that three components make up total cost:    

  •   Product     
  •   Setup    
  •   Practices    
Dosage Hand Hygiene Total Cost

In this series, we’re looking into real-life examples to find out how hidden costs affect your facility. 

Total Cost of Dishwasher Descaling 

This case study is specific to facilities in areas with a lot of limestone.  

Limestone causes a phenomenon called ‘hard water’. This means that the water is high in dissolved minerals, mostly calcium and magnesium.  

Heating hard water in a dishwasher causes solid calcium carbonate (also known as ‘scale’ or ‘lime scale’) to deposit on the dishwasher walls, in a similar way to what you might recall seeing in your conventional kettle. 

Scale is in essence an insulator and therefore reduces the efficiency of the heating elements, as well as interferes with the operation of automatic chemical dispensers in dishwashers. A service process known as ‘descaling’ removes these deposits.  

So, what happens if you don’t descale every two weeks? 

The Cost of Scale Build-Up 

In the commercial kitchen we studied, the dishwashers ran on automatic chemical dispensers.  

An electronic sensor (probe) inside the dishwasher measures the amount of alkali in the water that touches it. When it detects low levels of alkali, it tells the dispenser to release more dishwash chemical. 

 This dishwasher’s probe was completely covered with scale (which is an insulator, as noted above) and couldn’t detect any alkali in the water at all, even though the alkali was in fact present, so as a result it was calling for more and more chemical to be pumped into the dishwasher that was already cleaning well, therefore increasing costs and wastage. 

So, what were those costs? 

Cost Calculations – Scale Build-Up 

For normal operation, this facility would use one bottle of Machine Dishwash Liquid every 10 days.

  When the scale built up, they went through one bottle every day.  

You can already see that this is ten times the cost! Let’s go into the actual numbers, though.

 Chemical Price (5L bottle) Usage (5L bottle) per 10 days Cost per 10 days 
Normal $36.15 $36.15 
Scale $36.15 10 $361.50 

More than $300 extra cost just because of scale build-up on a dishwasher probe.  

This example is only for two weeks. If you left this unchecked, you’d be adding thousands of dollars in extra cost. 

Cost Calculations – Descaling Service 

There was another cost, but this one was of time.  

The descaling process takes 13 minutes for a trained Veridia professional, so we’ll assume it could take up to 20 minutes for a kitchen staff member. 

Here are the steps that take up the time: 

Step Time Taken 
Empty Dishwasher (Crockery, Cutlery) 30 seconds 
Empty Water out of Wash Tank 1 minute 
Flush with Clean Water 1 minute 
Fill Dishwasher with Water 2-10 minutes (subject to specific machine operating efficiency) 
Wait for Dishwasher to Reach Operating Temperature (60°C Wash and minimum 82°C Rinse) 1-6 minutes (subject to specific machine operating efficiency) 
Put Descaler Chemical In 30 seconds 
Run 2-6 Cycles  3-9 minutes (depending on extent of scale build-up) 
Drain Dishwasher 1 minute 
Flush with Clean Water 1 minute 
Refill Dishwasher 2-10 minutes (subject to specific machine operating efficiency) 
TOTAL 13 minutes 

In facilities with hard water, dishwashers need to be descaled every two weeks to keep them running efficiently. 

In this cost comparison, we’re contrasting the cost of staff time versus Veridia’s complimentary service. 

 Time per service (m) Annual services Annual time (h) Cost per hour Annual cost 
Staff 20 26 8.67 $25.00 $216.67 
Veridia 13 26 5.63 $0.00 $0.00 

Veridia’s free descaling service means 8 and a half hours extra for your staff, and over $200 in wages saved.  

Veridia staff will descale regularly to cut downtime for your dishwashers. 

This case study shows us: 

  • The cost of neglecting services is high. If your provider doesn’t proactively maintain your equipment, you could be losing out. 
  • Staff time is better spent in tasks other than equipment maintenance, especially if your provider doesn’t charge a service fee. 

Get in touch to talk to our descaling technician and find out if your dishwashers are costing you. 


 Chemical Price (5L bottle) Usage (5L bottle) per 10 days Annual Usage Annual cost 
Normal b x 36.5 = d a x d = f 
Scale c x 36.5 = e a x e = g 
 Time per service (m) Annual services Annual time (h) Cost per hour Annual cost 
Staff q x s = t t x v = y 
Veridia r x s = u u x x = z 

Leave a Reply

Subscribe to our newsletter


Other Veridia Insights.

Your Guide on the Five Moments for Hand Hygiene

Get the free guide and printable toolset now by filling out your details below.

Veridia Research Paper: Every Minute Counts

Get the free research report by filling out your details below.


Download the Rapid Antigen Test Product Specification Sheet


Download our webinar summary for more detail on how to combat modern slavery with focused reporting.


Infection Control
Resource Package.

Free of charge, just fill out your details below to gain access to your resource package now.