"George E. Cawthon" wrote in message
...
Mike wrote:
We're are leaving home soon for a one week vacation. I plan to shut off
the main water supply and gas water heater. (We recently had a leak in
the pipe leading to the water heater. So I want to be safe).

Somebody also suggested that I open a hot and cold water faucet (after
shutting things off) and drain to release some pressuse in the system .
But I was also told that do this way it may create some vacuum in the
pipe system that might damage the pipes.

My questions:
1) Is it okay to just turn off the water supply and water heater
without releasing the pressure?
2) If not, is the vacuum a concern?

I searched the group and couldn't find a complete answer. Help will be
appreciated.

I shut off the water at the main and open the lowest level faucets to drain
what water wants to come out. It's more than just for relieving the line
pressure. Worst case scenario is that if your heat fails and the water
filled pipes start to freeze. The potential for a busted pipe obviously
decreases if the pipe isn't completely filled--no guarantee, but why not
increase the odds in your favor. BTW, with the main off I also open the
washing machine valve (single lever). Flush the toilets after shutting the
main valve. if gone for a long period of time I get some RV Anti Freeze and
put it in all the drains--sinks, washing machine, dishwasher, toilet, shower
etc.