"phaeton" wrote in message
oups.com...
relieve the pressure

Since this is downstairs and there is upstairs plumbing, does that mean
opening the a sink valve on both levels to let the water in the pipes
upstairs drain all the way down also?

That should do it

Any special attention to the gas boiler and gas waterheater when
turning the water off? I suppose that if either of those decide to
drain out and then fire up it wouldn't be good for them.....

Won't matter for the water heater; though there is a small possibility that
the heater will put some pressure in the line you are working on. It is not
a big deal either way, but you might as well turn down the heater
temperature to stop it from turning on.

I don't know anything about boilers, but would guess that just turning your
thermostat down will take care of it.