"MRS. CLEAN" writes:

When clothes aren't drying, it's either the element or the spinning.

But, this is a new dryer.

Could it be the vent is clogged after 30 years?

Yes!

This is quite a fire hazard too by the way. One of the leading
causes of home fires if memory serves.

It vents into the attic.

That's trouble too, for different reasons. The moisture will not do
good things for you rattic. Might want to check your attic for
indications of mold, and get someone to extend that vent up to the
roof with a proper roof cap.

How do I clean it out?

There are kits with round brushes, and flexible shafts available at
appliance stores, big box home depot like places, wal mart too I
think.

--
Todd H.
http://www.toddh.net/