I went somewhere and when I came home, my filter was off and the place around the impeller was very hot.

What kind if filter is it? Brand, size etc

Its a regent 10-20 gal and it filters a 12 gal tank with one fish in it.

Have you tried pulling it apart? The reason I ask is I have hang on filters and find that they sometimes stop working when a lot of gunk gets stuck in the impeller shaft.

So if you can pull it apart and just rest the media in some tank water then you can try cleaning it thoroughly (not the media tho - you want to keep the good bio bugs)... You should see a plastic impeller and you can usually take it out - then clean down the shaft with a q-tip and rinse well.

Hopefully this is all it is so worth giving it a try

I agree, giving it a good clean is the quickest way to see if something bigger is wrong. My aquaclears get gunk stuck in the propellers from time to time and I have to give them a good clean.

Yeah, try cleaning it. When mine stops, it's because either the intake tube is clogged or the impeller has something wrapped around it.

Go for it, GFL10!! You can do it!

The first time I took it apart, I thought it was dead and, what the heck I'll give it a shot!!Well, I was shocked that when I cleaned it all up & put it back together it worked EVEN BETTER! (Probably had been getting clogged up for awhile!)

What kind of substrate do you have? I hope its just clogged...I have a 30-60 regent on my tank!

One other possibility - a power outage. Some filters don't jump back on their own, simply because the water that was in the filter got drained back into the tank, and the impeller can't pump the water back up.
Since the impeller part is very hot in your case, I would assume that is what happened. If the impeller simply would stop because of beging clogged, then it wouldn't get hot, since it isn't running in the first place. Lack of water however makes the impeller run hot.
What I usually do, besides taking it out and cleaning it, is just let it rest for 5 minutes unplugged, then add water into the filter and plug the filter back in. Works like a charm....

Thanks guys.I took it apart and I foung a very long piece of hair wrapped around the impeller.I took it off and it works.Thanks.

Congrats!! Now you are an offical fixer dude!!