> Also, does the heater coolant loop need to have constant flow for the
> Subaru system to work well over time?

chuck,
i would strongly recomment that you keep a constant flow through the
heater coolant loop. it seems to me that if the cooland just sits in the
pipes, there is more of a chance that rust or corrosion could get into the
system.

my $.02 worth

Sudhir H. Desai                         1984 VW Vanagon 3.4 liter Chevy V-6
cdes@welchlink.welch.jhu.edu            1996 Subaru Outback 2.2 liter flat-4
sudhir_desai@geocities.com              1997 Jeep Cherokee 4.0 liter I-6
ICQ# 8255956
http://www.geocities.com/MotorCity/Speedway/1889