pressure relief valve releasing water

[gene]

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

[HarryS]

I had that exact problem a few months ago. The water heater worked fine for years and then suddenly began to leak from the pressure relief valve. The leak would generally occur just after a heavy use of hot water. I figured the pressure relief valve had become defective so I replaced it. The new valve did exactly the same thing. So, I purchased an expansion tank, installed it and the leaking at the valve stopped and hasn't occurred since. When I installed the expansion tank, I also installed a pressure gauge to monitor the water pressure. It was initially at about 60 psi, so I reduced it at the pressure regulator valve to about 50 psi.

I strongly suspect that the water company had increased the pressure or had installed a check valve in the line (possibly when changing the water meter). I also suspect that water companies are strongly opposed to any water being forced back into the main lines because of possible contamination problems and so they are prone to installing backflow preventors. For all I know, water meters have backflow presentors built in now days.

Harry

[egou]

[Don Young]

The rusty water is probably caused by rusting of the spring and other parts in the outlet of the valve. Depending on how the outlet is pointed, some amount of water likely stays in the outlet where the spring is located. Opening of T&P valves is not generally recommended for this reason. Don Young