Plumbing winterizing question

[davidkerryedwards]

Some of you may recall I posted a question about a problem I was
having with no water thru the hot water lines. I figured out that
problem after talking to Tom Warner. The valve labeled 'Hot Water
Drain' in my coach is actually a hot water tank/line fill valve. If
that valve is not depressed with the cable control, water does not
enter the hot water lines. Once depressed, everything worked fine.
But I have a conceptual question about winterizing. When the air is
blown into the system via the electric valve, how are the hot water
lines blown out since the air has (?) to pass thru the hot water
heater before pressurizing the hot water lines? It seems the hot
water heater would absorb a lot of pressurized air before there was
enough oomph to blow out all the hot water lines.

Kerry
82 FC35
Denver