The Remaining 5 Items That Can Damage Your Dishwasher

6. Cast Iron Cookware

Dishwashers remove the protective seasoning layer and leave cast iron vulnerable to rust.

7. Insulated Bottles and Travel Mugs

High heat can damage vacuum seals, reducing their ability to keep drinks hot or cold.

8. Plastic Containers

Some plastics warp under high temperatures, while others may release unwanted chemicals if they’re not dishwasher-safe.

9. Aluminum Cookware

Aluminum can discolor, become dull, and sometimes react with dishwasher detergent.

10. Copper Pots and Mugs

Copper quickly loses its shine inside the dishwasher and may develop permanent tarnish.

Final Tip

The repair technician left me with one piece of advice I’ll never forget:

“Just because something fits inside your dishwasher doesn’t mean it belongs there.”

Taking a few extra minutes to hand-wash delicate or valuable kitchen items can save hundreds of dollars in repairs and replacements.

Now, every time I load the dishwasher, I double-check what’s going inside—and hopefully, after reading this, you’ll do the same.