There are a number of different reasons why your dishwasher isn’t drying your dishes properly. In some cases it’s due to a technical fault but most of the time the problem is actually caused by user error.
Loading your dishwasher properly and using the correct detergent and rinse aid can often fix the problem without the need for any troubleshooting steps or expensive repairs, and if your dishwasher is suffering from a malfunction you’ll likely notice other symptoms of the problem long before the drying stage.
How Do Dishwashers Dry Dishes?
The method your dishwasher uses to dry the dishes is very simple. The hot water used during the wash will heat up your dishes (with the final rinse cycle reaching the highest temperature). As the water is drained at the end of the program, the heat retained by the dishes will cause any residual moisture to simple evaporate, leaving your dishes dry.
The basin of most dishwashers is made from stainless steel – this will cool faster than your dishes and draw moisture down to the bottom of the dishwasher, aiding the drying process. The reason your dishwasher seems to do nothing for a while at the end of a wash program, and might beep at you if you open the door too soon, is in order to retain heat and keep your dishes hot for as long as possible.
So, the way your dishwasher dries dishes is pretty straightforward – what can go wrong?
- Different materials conduct and retain heat differently. Glass is a great heat conductor and will get really hot during the wash, whilst plastic cannot hold heat as effectively and therefore won’t dry as well. If you have a lot of plastic dishes wash them on a separate load from glass and crockery to prevent them slowing the drying process.
- Loading your dishwasher properly is important for getting your dishes fully dry. A cup or glass placed upright in the rack will not only be full of dirty wash water at the end of a cycle, but will also hamper water evaporation during the drying sequence and stop the rest of your dishes from drying as well!
- Some modern dishwashers can detect how dirty your dishes are and adjust the washing time accordingly. Cleaner dishes going in means a shorter wash cycle, lower temperatures, less effective drying. Scrape, but don’t wipe down your dishes before putting them in the dishwasher – the dirtier the better!
- Fast or ‘eco’ programs invariably use lower water temperatures to speed up the wash. If you want dry dishes then running a full, hot program is always going to give the best results.
Use Rinse Aid!
The way rinse aid is marketed causes confusion for a lot of people. It’s often advertised as a product to get your dishes extra sparkly but it’s main purpose is to ensure your dishes dry properly.
Added during the final rinse cycle, rinse aid breaks the surface tension of the water in the dishwasher, effectively making your dishes water repellant and making the evaporation process more effective.
Is the Water Getting Hot?
If a technical fault is preventing your dishwasher from drying the dishes properly then it will almost certainly be related to water temperature. If the water is not getting hot then your dishes won’t wash properly and obviously won’t be heated up to dry by evaporation.
If your dishwasher is failing to heat the water then it will usually detect the problem and display an error code.