On Sat, 12 Jan 2013 10:35:12 -0500, "TomR" wrote:


I am not sure why you are trying to avoid using the "main shutoff valve",
and I am not sure if by "main shutoff valve" you mean the water shutoff
valve outside at the street or the "main shutoff valve" near where the water
comes into your home.

Sometimes, if the "main shutoff valve" doesn't completely turn off the
water, you can turn it off as much as possible, then open all the valves in
all the sinks and tubs etc and leave them open while you change the hot
water valve for the bathroom. But having everything else open, the pressure
drops in the system and you may be able to get whatever small flow there is
to only come out in the sinks, outside faucet, etc. that are below the level
of the bathroom vanity that you are working on. And, if you replace the
bathroom vanity hot water valve with another screw-on type (if that is what
happens to be there), or you replace it with a shark-fitting slip-on type
that requires no soldering, you can probably change out the hot water valve
that way. Then go ahead and do the work on the faucet change.

Good luck.


As often happens, not enough info has been posted.
There are many variables. Nobody mentioned, including me, that water
heaters commonly have in inlet valve. If that closes well you've shut
off all hot water even with the main entrance valves open.
Even city-owned Buffalo box service valves can be inoperative.
I replumbed my last 2-flat because the 50 year-old galvanized was
limed up and I had real bad flow from all the faucets.
Worked the entrance valve open/close repeatedly, but never stopped the
flow, which was maybe .5 GPM from the basement laundry tub faucet,
which was lowest and closest to the entrance valve.
Worked the Buffalo box valve repeatedly, and when bottomed it didn't
perceptibly change the flow. Since I never got many turns on it I
figured it was bad, but didn't know how bad.
Since I wasn't about to call the city and possibly get into
permitting, inspections, etc. I just forged ahead, Never been a
licensed plumber.
Made up a new entrance valve with taped nipple in, valve open.
Had a buddy hold a washtub under the union and prepare to catch the
water when I removed the old main entrance valve from the lead service
line.
Broke the union and moved the pipe aside. A bit more than the .5 GPM
coming out of the open laundry tub faucet.
But that was only what the closed valve was letting through.
Put the wrench to the valve and removed it.
A gusher shot clear across the room. My buddy got soaked trying to
put the washtub in front of him. The gusher hit him hard.
Since I had the new valve open and fitted, I got it on real quick,
closed it, and tightened everything down. I got soaked by spray too.
Probably let a few gallons of water loose in the 10 or so seconds it
took to get dry connected
"Closing" the Buffalo valve did hardly anything.
The limed up pipes is what fooled me. Almost completely closed in
some places.