[TaoJones]

In my experience, having full-timed through several winters in Montrose, Colorado since about 2012, I can confidently say that a heat-wrapped supply hose that does not lose electric power will never freeze. On those occasions where I've had no running water on first rising, the issue has always been either where the supply hose connects to the RV (a brass 90° elbow, in my case, that I've sometimes done a less-than-adequate job of insulating) or, the park's supply hydrant.

If the hydrant is not properly insulated and/or heat-wrapped and properly powered, a frozen plug will form in that on/off valve. It can be thawed by applying heat from a heat gun directly to the valve, or if the daytime high gets even up into the mid-20°s, Mother Nature can thaw it to the point where the pressure behind the frozen plug will push it into the heat-wrapped supply hose where it will quickly dissipate.

For a frozen plug inside my 90° brass elbow, I simply turn off the water at the hydrant, disconnect the hose from the elbow, remove the elbow from the city water inlet on the RV and take it inside where boiling water applied to it in the kitchen sink quickly thaws the frozen plug. When I reassemble the elbow and supply hose, I do a much more attentive job of insulating the elbow.

There are those who maintain that leaving a slow drip coming from a faucet will prevent the formation of any ice plugs in the fresh water supply system. In those places where it doesn't really get very cold, or doesn't go below freezing for very long, that theory works . . . but wastes water. In places where life-threatening cold snaps are not an unexpected occurance, it will only work up to a point. Then the supply will freeze up regardless unless the faucet is opened more than just a slow drip.

As a child of the western US, just the thought of wasting water for any reason is completely alien to my thinking. Please don't do it - because there are much better, less mindlessly wasteful, ways of coping with an interruption in the supply of fresh water caused by the formation of an ice plug somewhere in the system.

It doesn't take much of a frozen plug to develop in the water supply to stop the flow of fresh water, but it also doesn't take much effort to remedy the problem. Doing nothing to get water flowing again during a prolonged cold snap is asking for a problem that is much more difficult to rectify. Deal with the interruption quickly while the problem is still minor.

TJ