Why isn’t my dishwasher drying?

Understanding how rinse aid works in your dishwasher may be the secret to consistently dry dishes

by Kyle D. Mirka, Owner

I’ve heard the story a thousand times over the last ten years of selling dishwashers. While the details vary, the customer complaint boils down to the fact that their new dishwasher isn’t drying dishes like their old dishwasher.  Typically, their old dishwasher was between 10 – 25 years old and was of American design, with a large exposed heating element at the floor of the tub. Those heating elements not only consumed huge amounts of electricity, but they also were the reason you’ve probably always put plastics on the top rack and never on the bottom. If you’re anything like me, your mom taught you that plastics melt if they are put on the bottom rack – and mom was right!  Many dishwashers today still have an exposed heating element, and while they’re not quite as bad as they used to be – they are still hot and still suck up the energy.  More and more, manufacturers are turning towards the more popular European design which heats its water with an in-line water heater tucked in the sump of the dishwasher, where you can’t see it.  This is very efficient at heating water and allows you to put plastics anywhere you please, but this type of heating system doesn’t allow for a heated dry cycle.  That’s where rinse agent comes into play.

The most common brand of rinse agent is Jet Dry - and no matter what brand, almost all of them are blue in color, but it definitely doesn’t have to be.  One of the best rinse agents is made by Miele and is clear. Rinse agent is released during the dishwasher’s rinse cycle and effectively alters the surface tension of dishes allowing for water to sheet off.  In dishwashers that are without an exposed heating element, this step is critical in achieving dry dishes. Those models, which come from brands like Miele, Bosch, Viking, Blomberg, KitchenAid, Electrolux, Asko, Fisher & Paykel, and more, are using the heat from the water that was in the tub before it was evacuated to dry the dishes. As the outer walls of the dishwasher cool, the minimal water that was on the dishes then condensates on those cooler dishwasher walls, leaving your dishes dry.  Usually, the manufacturer leaves the rinse agent dispenser on the middle setting and it's just right for optimal performance, but rinse agent doesn’t do its job if there is either too much dispensed, or too little.  It shouldn’t take you long to dial it in, and as an added guide, the harder your water, the higher the quantity of rinse agent will need to be dispensed.

You may also be wondering about the all-in-one tablet. Several detergent manufacturers are putting rinse agent in a soap tab.  These tend to work just fine.  Just keep in mind that if the rinse agent dispenser is full and you use an all-in-one tab, most likely too much rinse agent will be introduced to the environment, and you’ll end up with wet dishes.

Many dishwashers will alert you when the rinse agent needs a refill, but if yours doesn’t, it will be very obvious when you’ve run out. I currently have a model that doesn’t have an indicator and wet dishes are a dead giveaway to being out of rinse agent.

While consistent use of rinse agent takes care of almost every complaint of wet dishes, if you’re shopping for a new dishwasher and you’re still afraid of losing your “heated dry” cycle, you can also seek out models that have a fan within the dishwasher that aids in cooling the tub and increasing the condensation factor, therefore, drying that much better. Typically, this is only a feature in high-end dishwashers, but one of those high-end dishwashers may be the best fit for you.

The bottom line is this - rinse agent is needed for almost every dishwasher for sale today, and the having the right amount dispensed is the secret to dry dishes.