A gooey mystery: Dark liquid leaks from the dishwasher

Question: The other night, I turned the dishwasher on as I usually do, and after a while a little bit of dark liquid dripped out of the right bottom corner of the machine and onto the floor.

I cleaned it up, thinking very little about it, but the same thing has happened every time I have used the dishwasher since. In fact, it is getting worse, and I now have to put a bowl at that corner to catch the goo.

What should I do? The dishwasher is about 10 years old and works perfectly otherwise.

What do you think the problem is? Is it expensive to fix? Whom should I call, or should I try to fix it myself?

Answer: The problem is, I don't make house calls, so I have to diagnose these things without visiting the patient.

My best guess is that the bottom door seal is worn out enough to have stopped performing properly and needs to be replaced. It happens.

The cost of repair, which includes ordering the correct seal for that model, can vary considerably. A new seal itself isn't usually expensive, and your dishwasher is new enough so you wouldn't need to do much searching for a replacement.

From what I see in online videos, some brands accommodate work by do-it-yourselfers who follow directions that include shutting off the power. Other brands seem to beg for a professional repair.

Using a pro typically guarantees a quick repair despite the cost of a service call, labor, and parts needed. Look on the manufacturer's website to see what's involved.

I usually leave plumbing and electricity to the professionals, although if the job is simple and not risky - clearing a jam in the garbage disposal, for instance - I'll do it.

The late Marcel Paillaird, who was my plumber and the subject of many columns over the years, once spent hours correcting a sink repair I had tried to undertake myself. He gave my wife his cellphone number as he was leaving for his home in Hatfield.

"If he ever gets within five feet of a pipe again, call me immediately and sit on him until I get here," Paillaird told her.

aheavens@phillynews.com or write him at Box 8263, Philadelphia 19101. Volume prohibits individual replies.