Note my original post said put valves far away from tank, this
elminates soldering on valves. which with water on the other side
wouldnt work anyway...or you couldf use unions..
around here code now requires a pressure tank and checkvalve at meter
to prevent siphoning from say a abandoned swiimming pool water back
into the system.
The valve is about 3 feet from the tank. Just put valve on
the cold side. The tank connection is via flare fitting. I
moved the flare to pipe adaptors from the old tank, so that
made the connection at the tank. So far, far as I know, no
leaks. The pilot lit up, and then the whoof of the gas
flame. Sounds like I'm in hot water for a few more years.
You are aware of "The Dumb Ass Effect"? You will
know better than to shut off both valves while
the heater is in operation but "some dumb ass"
will come along and turn the damn things off
when they're not supposed to.
Possibly damaging the T&P valve. It's a safety valve not
meant to open over and over again. When the valves are
popped open more than a few times, they will tend to start
leaking. Besides, if the valve doesn't go outside or to a
drain, you will wind up with a very wet floor to mop.
Why is the T/P valve going to open?
It will only open (when both inlet & outlet valves are closed) IF the
water heater over heats due to a failed thermostat.
T/P valves only open when T or P exceeds limits.......
What's the big deal if BOTH valves are turned off while the water
heater is in place?
How is that any different than when all the hot water valves at all
the fixtures are off?
The water heater will heat the water to the temperature set by the
thermostat & shut off.......just like it always does.
EXPANSION! I've had to install expansion tanks on water
heaters where the plumbing system wasn't large enough to
accommodate the increase in volume when the water is
heated. The T&P valve will pop open all the time until
it starts leaking. I wish I could get my friend who is
a master plumber with many years experience to chime in
to this group. When you've worked in the construction
and service industry for several decades like I have,
you will tend to absorb a lot of knowledge by observing
and asking questions of other people who work in many
different fields and trades. Ben there, done that, seen
that applies to anyone who's been around long enough,
unless they're in a coma. "The Dumb Ass Effect" is why
I put locks on valves, safety switches, electrical panels
and a myriad of other devices. Warning signs encourage
dumb asses to play with things. Understanding dumb asses
has provided me with a lot of entertainment. I once hooked
a fire horn to a latching switch that was marked "DO NOT
TOUCH THIS SWITCH". I can't count the number of times I
laughed at some poor moron who just could not resist the
temptation to fiddle with it.
You are correct.....
IF the water heater is cold (ie not at operating temp) WHEN BOTH
valves are closed.....
YES the T/P valve will relieve the pressure due expansion IF BOTH
both remained closed during this "procedure"
and if IF the pressure exceeds the limit of the T/P
btw water heater tanks are not infinitely rigid......I'm too lazy to
calc the volume change from 75 psi to 150
btw this would a one time event unless your "example dumb ass" keep
opening & closing the valve and letting the water.
my condolences for your pain of having to work & interact with dumb
I have fun trying to make things more idiot resistant and since there
are a lot of idiots, I dont run out of fun.
one way to make the two valve installation more idiot
resistant.....remove the handle from the outlet ball valve
The problem with removing the handle of a gate valve
is that the dumb asses have discovered vice grips. I
like ball valves with a lock around them. There are
locking enclosures that wrap around valves but the
drain bamaged know how to use chisels and hack saws.
More work for me.
My further condolences.....
the breed of "dumb asses" that have access to you & your
installations are way dumber and more persistent than my SoCal "lazy
I will continue to do my installations per my designs since all my
installations seem to be inaccessible to your types of dumb asses. I
have never suffered from the efforts of your types of dumb asses.
Although I have see some majorly dumb things done .......... not in
the league you describe.
Luck or design? Who knows.......
btw I never mentioned removing the handle on a gate valve.
I know you wrote ball valve, that's easy to turn with
an adjustable wrench but any valve with a relatively
smooth shaft won't stay that way. If you're familiar
with refrigeration valves, you know that some jerk
without a square drive wrench will put vice grips,
pliers or an adjustable wrench on the damn thing and
I was in an old country shop, one time. They had a nice neat
wooden plaque that said "in case of fire, lift flap". I did.
Under it, nicely painted, said "I said, IN CASE OF FIRE,
I like you one with the fire horn.
Enjoy the learning experience...?
CY: so, so, true.
You've been around the block more than a few times - hell,
grooves in the sidewalk!
CY: This won't be my first water heater.
What does snow have to do with sticking a
shut-off valve on the installation? I'm assuming the water
inside in snow country. It couldn't have taken more than an
CY: Trailer life. The WH is in a compartment that only
access from outdoors. I'm standing on a step stool. In 20
degree wind, working in an access door that's only about an
inch wider than the WH. It's not as convenient as working in
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