Water Heater P&T valve leaking - pressure coming in from city

[demonrow]

I found a post in this forum that appears to answer my question, but I wanted to start a new topic to get a better grasp of the big picture.

 

My p&t valve line goes up and out to the patio. There appears to be water there (maybe 8 to 10 oz) every morning (after showers?). Here's the post that leads me to believe its either build up or too much pressure.

 

http://appliantology.org/topic/27317-water-heater/?hl=p

 

So if it is too much pressure, here's my question; how much pressure should be coming in from the street? Its City water. Is this a measurable thing, for a non-plumber like myself? A way to test it?

 

We have a toilet that chronically runs for a second or two occasionally (I've replaced the entire tank kit by now) that also made me think I had too much pressure.

 

I'm familiar with the valve to limit the incoming pressure, but only in passing. I say hello. Its silent...

 

Any advice would be grratly appreciated. Even if its "Dude, call a plumber..." I can post pics and models #'s, but for now its more of a general, philosophical discussion.

 

Thanks,
D

 

 

[certified tech group 51]

Measure the water temperature, is it hot????..............Should not be over 120 degs. F.........Could be a failing  thermostat  letting the water get to hot after long heating cycles.......The P/T valve does not limit incoming pressure...............The P in P/T valve is for  pressure caused by   the  water system  ( city or a well pump ) exceeding the  valves rating about 150 P.S.I.....................The T in P/T is for temperature......... .If the temp exceeds it set  temperature , about 210 degs..................... possibly from a runaway condition of the thermostat(s)...................The big box stores have a pressure gauge that threads onto a standard garden hose bib, measured from out side or attach to the hose bibs at the washing machine................Gas or electric?????.

[demonrow]

Thanks. Its a gas unit. I'll check the temp. The toilet running leads me to think it might be pressure, so I'll look into the gauge. Appreciate your help; I'll report back.

D

[RegUS_PatOff]

click on picture

my city water pressure is 42 psi

[demonrow]

Cool, thanks!

[demonrow]

Hey,

 

Finally got around to testing this. Got the pressure gauge. Pretty cool. The overflow pipe from my water heater doesn't have the threading. Put the gauge on my outside spicket and got about 68 psi. It spiked to 120 when I first turned it on.

 

Have not measured the water temp coming out of the heater, but I usually shower with no cold whatsoever, can't be too hot. We have (or at least had) small children, so we've always run it set just under "hot". Guess I could use a meat thermometer....

 

I'll report bck.

 

Thanks,

D

[RegUS_PatOff]

... Guess I could use a meat thermometer....

 If you have a Harbor Freight Store near you,

$ 3.99 sometimes on sale for $ 2.99

[JJ Surfer]

Your hot water heater Should have a max pressure rating, I'll bet 120 psi is close to its max. Either an adjust to your pressure regulator or replacement might be needed.

[olyteddy]

Is there a backflow or check valve on your water supply? If so, you may have to add an expansion tank to the supply line of your water heater.