I have a 4 year old full sized stacked unit.  Looks like regular washer dryer stacked.  Its made by Frigidaire.  The problem is in the dryer, the heating element smells like its burning.  Also, its on all the time no matter what temp setting is at and there is a rattling sound as if part of the element fell off.  

Any help here would be great,  Joe

Thanks

You could have a shorted element. just replace it. And if it [element] stays on all the time DO NOT USE THE DRYER. Mine almost caught on fire this summer from the same thing and I caught it just in time. Smoke was billowing out from the vent and the dryer was so hot it could not be touched for almost an hour. If there had been lint buildup [I keep my lint trap and vent clean] I'm pretty sure it would have gone up.

yup, heating element is very easy to replace.

Frigid-scare are not too bad to replace the coil. If its the coil one that is in the back that you have to thread through porcelain loops, START with the middle loop and work your way back to the terminals. I found that if you start with one of the terminals then thread the element through, it wont be even thus creating "hot spots" and lessen the life of the element. If it is the box element already wired, all you have to do is plug it in... you are good to go.