Dishwashers and Hard Water

This article is about  what to do about your dishwasher when it becomes overlaiden with mineral deposits.

 you live where the water is hard with alkaline then you are probably aware of the havoc it has on dishwasher performance.

Minerals will build  up inside the machine over time until finally it begins to block the ports in the spray arms which diminishes the dishwasher's  to clean the dishes well. When hard water reaches a high enough level of contamination you may see  your glasses or crystal ware starting to look as if it were etched. If left  unattended the etching can become permanent damage. I have seen in severe cases where mineral deposits had built  up down in the sump  area where it wasn't visible but nonetheless it had grown to the size of a golf ball.  Once hard water  prevents the circulating pump from moving enough water the machine  is pretty much done with serving any useful means.

The good news if there is something which can be done about it. So there's no need to go out and buy another machine. There are a few approaches to getting to the point where you can deal with the  problem on your own. With severe cases it may be necessary to hire a professional such as myself to open up the machine to perform some major cleaning first. Whether you get a professional cleaning and removal of the minerals in your machine or you do it yourself, or if the build up isn't quite as extreme as all that, then you will be ready for a routine maintenance.

In the following examples cleaning and regular maintenance is explained for a routine that you may repeat once every three months but the frequency can be modified to fit your needs based on the amount of hard water you may be dealing with.

In the areas I service there are cases where once every three months is about right. In this example you can do this right before you go to bed;

The machine should be empty  of all dishes.

First set the cycle on whatever would be considered the hottest setting such as "Pot and Pans" or "power scrub" or "sterilize". Go ahead and start  the machine without any detergent in it. The machine is going to do a short drain first before it fills. After it fills it will begin pumping. Most machines perform a short rinsing cycle before the actual wash cycle begins, so you will be listening for that second drain after te initial rinse. The machine will then fill again. Now it is primed for that long wash cycle. At this point open the door to stop the machine but don't cancel the wash. Now pour half a gallon of distilled white vinegar liberally into the bottom of the machine. Now just leave the door ajar overnight, allowing the vinegar to work on the machine. When you get  up in the morning just close the door and allow the machine to resume washing. In cases of extreme contamination one time with this method may not be enough and once the hard water begins to break  up it will seem as though the problem has gotten worse. Just start the machine and let it run for 20 minutes or so then cancel the cycle which will set  it into a drain cycle, then do it all over again, each time rinsing and draining away the stuff that is loose and floating around in the machine. If  there is still more issue with hard water then repeating the process with the vinegar may be needed. In most cases just once is all that is required.

I recommend vinegar because it is the most economical choice, however there are other products which work well and it should be your choice as to which product you prefer. CLR is a very good product as well. For those who don't know, CLR stands for calcium, lime and rust cleaner/remover.

I once repaired a dishwasher for one of my clients and I commented on how clear her machine was of minerals. She proudly told me that she uses a quarter cup of vinegar with every load of dishes.

There are some screens and a filter which I always clean in the sink as part of my routine. When treating for hard water I always bring one gallon of vinegar and a scrub brush. I pour half the bottle in the sink to use as a bath for the parts that I wash and the other half is  used on cleaning out the machine and finally running the machine to flush  out all the  particles.  

Another problem as a result of hard water is something I have seen in rental properties that sometimes sit for 3 months or more between contracts. Letting a dishwasher sit unused for long periods in the presence of hard minerals will allow etching of the main seal in the pump which can ultimately cause leaking. In many cases the leaking is slow enough that it goes on undetected. The final result is etching of the shaft and bearings in the pump and in even more unpleasant events the leak can become larger to the degree of causing damage to the surrounding cabinets even before anyone has become aware of the  leak. These issues could be avoided along with their costs simply by  running the dishwasher once a week during those times of non use.