Thanks to all - This was second system installed by the same company. It has not gone well. The first system and it's install was flawless. This attic install has been a nightmare. And as you have pointed out - not for equipment issues.

The new system included an upgrade from 2.5 ton to 3 ton capacity in hope to achieve better airflow in the bonus room which is furtherest away from the unit and (traditionally) located over the garage. My installer suggested that I get the system up and going before making more improvements. Now I am considering enlarging the plenum and upsizing the aging flex tubes (over 20 yrs old).

Since the horizontal unit has been nothing but trouble should I consider changing the setup to a vertical orientation when I have the flex changed out? There is plenty of overhead space in the attic.

Additionally I have located the documentation left for the system but find only a user's information guide for the Clean Air Effects. I'll go looking for an on-line source for the installation instructions but would appreciate anyone posting this who may already know the online link.

Thanks once again to all.