Hi Cvm

The way the dryer works of course is that the heating coils heat air, the drum tumbles the clothes and the motor connects to a blower which sucks in air from the outside where it is heated, passes over the clothes absorbing moisture and is expelled to the outside.

Let's assume to begin with that your dryer heating coils are working as they are supposed to, and that your drum is tumbling. Let's also assume this is happening on time dry. This means the problem is in the air flow, which is the most common problem when the dryer is not drying correctly.

You need to open up the dryer and clean out the venting system. This means taking the cover off of the blower and cleaning it out. When you do this you need to inspect the blower to make sure it is not damaged and is turning correctly. If this is your problem you an expect to find a lot of lint, or something blocking the venting/air system or a bad blower.

Put the system back together and see how it does. Let's us know the results, and if you still have a problem we will go from there.

Good luck.