HOUSTON -

Your washing machine is supposed to clean your clothes, but several class action lawsuits against some of the biggest manufacturers claim thousands of machines have a design flaw that causes them to grow mold inside.

These lawsuits are pending against Whirlpool, Kenmore, LG and Bosch in regards to several models of each company's front-loading washing machines made from 2001 through 2008. Critics of the machines say that the way the washtub lays doesn't allow it to properly air out and dry. The result is a moldy, smelly mess.

Bill Anderson of Bill Anderson Services repairs front-loading washing machines; and he says the complaint about the moldy smell is nothing new.

"They have all these little cracks and crevices in the boot," Anderson explained.

The Whirlpool lawsuit reads, "These washing machines have serious design defects that cause them to accumulate mold and mildew and/or residue or growth within the washing machines."

One solution is to leave the door propped open between washes to allow the tub to dry out. You can also use a towel to wipe the inside of the door seal or boot.

The lawsuits allege that manufacturers knew about the mold issues, but failed to tell consumers or repair the machines under warranty.

Anderson, who is not connected to the pending suits in any way, wouldn't go as far as to say the problem is the result of a design flaw, but he did offer this.

"Let's put it this way. Some of the manufacturers made it without the drain holes to drain the boot. And then they had to go back and change the design to do that," he said.

You can still join one of the class action lawsuits. For more information, click here.

You can read the statement the washing machine manufacturers provided to NBC News at this link.