Thank you! You're doing more for me than McQuay is. You do hear something. I never paid attention to a "whoosh" per se, but you can definitely tell when it switches over to heat.
I've got the thermostat manual I haven't found anything that will help. I think the problem is at the receiver end. The thermostat does not have an "auto" it is either HEAT, COOL, or OFF. It's set to HEAT and I've set it to HOLD the temperature. Since it's a wireless thermostat, half the booklet is about installing nodes.
If it helps, the booklet I have has the following info:
Operation & Maintenance Manual OM 897-1
Part Number: 668111002
Date: August 2009
The Heat Pump booklet info
Installation & Maintenance Data IM 985-2
Part Number: 669479302
Date: November 2011