I moved into my house a few years ago and did not realize I needed to occasionally test my hot water heat relief valve. I had never tested it before today. I also have never had any problems with it. It is a Whirlpool 40 gallon tank with a max working pressure of 150 psi. My house does not have a regulator or expansion tank so whatever pressure is in the city line is what my house gets (I think).
I tested it for the first time today. Before doing so I isolated it from the gas feed and the water inlet feed. It spurted out some blackish dirty looking water and then stopped. I closed it and reconnected all the lines and now it has a slow trickle out of the relief valve. I tried running the hot water out of several faucets for awhile but the leak continues. It did not leak before I tested the valve.
Any thoughts on what might be going on here?