Originally Posted by diyorpay
The pipe is draining into overflow pan. Overflow pan is not draining. Usually drain from pan is on side nearest your gutter. If you can access the point where drain drains into your gutter (outdoors, on a ladder), you can clear it with a long stiff wire or plumbers snake. If your gutters are totally clogged, they need to be cleared.
Not all condensate lines drain into the gutter. Especially not in my area. But good point as far as finding the exit point and snaking back to the unit.
Personally, I would cut the main drain line, cut out the old trap, install a new trap with a union before the trap so that it could be broken apart later (should be done every year) and the drain line cleared. Pvc pipe is very easy to repair/replace. some pipe, fittings and glue and you are back in business.