Hmmm, Jim,
I have inadvertently let the water tank/supply network freeze solid, &
unfrozen it w/ a heater in the westy during winter & not had any problems.
The pump did fail several years later, but I don't believe that it was the
result of the freeze,but because it was 25-30 years old at the time? I have
taken the pump out & worked the impeller by hand when it was stuck  & then
it worked fine.

Mr. BZ-on OEM faucet #2 & pump after 33 years-YMMV

On Sat, Oct 15, 2016 at 10:19 AM, Jim Arnott <jrasite@eoni.com> wrote:

> FWIW, I have had the system freeze. I have pre-85 Westies with the water
> pump under the sink.  If I don’t prep the system, in the spring I’m buying
> a new pump. Doesn’t hurt anything else, but water freezing in the pump
> kills it every time.
>
> Jim
>
>
> > On Oct 14, 2016, at 9:58 PM, David McNeely <davmcneely40@GMAIL.COM>
> wrote:
> >
> > I have never had the system freeze, and all I've ever done is drain
> > everything.  Since the trap is open to the air in two directions (I leave
> > the drain cap off in winter), and holds little water, it is ok -- or at
> > least mine has never cracked.  The beast does stay in the garage most of
> > the time in winter, but I drive it occasionally, and in below freezing
> > temperatures.
>

-- 
Tom Buese