Im thinking about the advice given to keep a trickle of water flowing on subzero nights.

If your water main did not have a check valve installed, or a faulty one, would the slight pressure differences of water moving ward away the freeze? Would that be the same as "leaving a trickle on"?

In my case, I had a faulty check valve replaced. In addition to the noise it was making, it wasn't shutting fully and there was a tiny bit of water flowing back and forth (as evident from the meter dial moved ever slow slightly in both directions). When the check was replaced, the meter dial now stands completely still. I wonder if that means keeping the water flowing on subzero nights is more important now?



Edited 1 times.

The movement of water would likely be so small that it wouldn't help prevent freezing.

When the water in the pipe gets cold enough, it will freeze, and the small amount of water flowing backwards would have absolutely NO effect on the water temperature inside the pipes.