Thank you for your answers. Frankly, I wasn't sure if the suggestions above were within my abilities as a diy-er. So, I've been muddling through with it taking 2 hours to dry an average load of laundry.
Lo and behold, new gas was delivered Friday and it is back to full heat, normal operation. ??? Bad gas? I don't know enough on the subject to really speculate, but it seems that this has fixed the problem for now.