Joseph Meehan wrote:
George E. Cawthon wrote:

Joseph Meehan wrote:

wrote:


Since last week every time someone takes a bath the T&P valve
discharges a small amount of water. When this happens, the water
looks a bit rusty. If I pull lever on the valve, the rusty water
will drain and for a day or so there'll be no more leaks, then it
starts again. I checked the water line pressure and it's at 60 PSI.

I've replaced the valve and flushed the tank for about 30 min - two
days later the leak is back and water is rusty again when the lever
is pulled.
Any ideas?

thanks,
GE


The valve is doing it's job, it is releasing pressure or opening
due to temperature. I would say that at 60 PSI, it is likely due to
the pressure. Back that pressure back to 40-50 and that should take
care of it.

But that doesn't answer why the valve all of a
sudden started leaking. Besides 60PSI is way
below what a T&P valve is set for. Could be
someone installed a back flow preventer, at the
street or somewhere in the house line. Otherwise
the original valve went bad.

The real point is that one should never trip the
TP valve with pressure in the line because it may
not seat properly. The best bet as a first step
with the new valve is to nearly close the supply
valve to the hot water tank, open the T&P valve to
let water flow for a bit to clean out any rust,
close the supply valve tight, and then let the T&P
valve snap shut. Might want open and let the T&P
snap shut a couple of times. Then turn then open
the water supply valve. Of course the new valve
may be bad. But if doing what I said doesn't
solve the problem, look for a change in the water
supply line, house or at the street.


Do you have a check valve somewhere?


Nope. Fortunately, there is no check valve or
backflow preventer in my house or at the meter.
So I never need to worry about pressure build up,
it will just be whatever the city line is. Also,
I have never lived where there was a pressure
regulator. Might need too though since a friend
of mine said they and a neighbor or two recently
had the TP start leaking and so they checked the
pressure. It was 190. They called the water
company which denied any increase in pressure, but
he knows they did increase the pressure to push
water over a small hill to another subdivision.
Fortunately for me that isn't part of my city
water system.

I didn't mean to address the problem of a check
valve/backflow preventer and the possible need for
an expansion tank since others had. Just that the
OP needed to revue whatever may have been done
recently to the system as part of his analysis of
the problem. And that pressure valves sometimes
won't seat properly when under pressure.