Can I just empty water tanks instead of winterizing?

rhagfo wrote:

Not true, if day time temps are in the mid 40's you can likely go as low as 28 degrees easly. What're doesn't freeze instantly when the temperature out side is 32 degrees.

Agreed. But I'm not talking about instant freeze. It only takes 5 or 6 hours for a small amount of water to completely freeze in the valves at 28 degrees. Unless there is a guarantee that will never happen in Portland? I don't know. But for the small amount of time and money involved, why take that chance?