joecaption

Sometimes simply lifting the trip level on the relieve valve and flipping it back down will reseat it. Water out of the tap should be no more then 120 Deg. if the heater is set to high it can cause it to leak or trip.

Redwood

The valve you are describing is called the T&P Valve. As Joe described many times raising the lever and snapping it back down will reseat the valve and stop it from leaking.

There are also 2 legitimate reasons why it may be leaking which will have to be checked if snapping the T&P lever doesn't work.

The valve opens when the temperature or, the pressure is too high, so those should be checked. If those are within the limits then the valve has failed and should be replaced.

Here is some reading on the subject...
The T&P Valve On My Water Heater Is Leaking

Thermal Expansion Tanks For Water Heaters

dtheobald

OK, I drained it, flushed it...a bunch of stuff came out of there...so I was hopeful. I fired her up and the popcorn popping sound...well, it sounded more loose, if that makes any sense. But the hissing came back. I dont have internet at my house, so I am printing those articles out redwood. Thanks.

__________________
Devin

dtheobald

OK, just an update if anyone is interested.
The pressure relief valve was shot. The hot water heater sounded very bad and was loud. So, my wife and I agreed to purchase a new one. I removed the old unit, and noticed that the pressure relief valve was removed from the side and placed on top of the hot water 'out'. This made it closer to the pressure relief drain out of the house, but it didnt seem right. Both hot water heaters have warnings about removing the pressure relief valve and placing it some where else...
Also, The water main into the hot water heater had issues at the stop valve. It wouldnt seat all the way, and it would leak when full open.
I removed the old unit, shut of the main to the house, and replaced the stop valve line into the unit. Turned the house water back on, no issues.
Then onto the installing the unit.
The pressure relief pipe was on the opposite side of the pressure relief valve, so I hade to run copper pipe from the wall, around the unit, and then up to the hot water heater. I braced the new pipe on the wall with a 2x4 and copper straps for added earthquake protection (I Hope).
Fired her up, and she runs great...whisper quiet, and great hot water.

Thank you gain for all of your assistance.

__________________
Devin

joecaption

I hope you installed a ball valve for a shut off. Shark makes one that just slips on over the copper pipe, no tools needed.
You could have saved a lot of trouble by using Pex to plumb the relief valve with a simple slip on Shark fitting.
I believe you will find it's code in CA that heater also needs to be strapped to a wall to prevent it from tipping over.