I've been hearing a hissing noise in my pipes for weeks now and I finally realized it was coming from the tankless water heater. I was out on the porch and I saw water dripping from the unit. When I opened it I heard the hissing noise and saw that the water was coming from the PRV. I pulled on it and let some water through (cold water) and the hissing and leaking stopped.
A couple weeks ago prior to this, I adjusted the pressure valve for the water coming into the house to reduce the water pressure. I was thinking that the pressure was too high because of the hissing and banging pipes. I noticed that the pressure is less coming from the faucets but I still got the hissing and the knocking has been significantly reduced.
Is there a problem with the tankless water heater or am I having water pressure problems? I'm confused because the pressure is just bearly strong enough for a good shower.