Yesterday I replaced my water heater. I also replaced the shut off valve to the water heater because that had started to leak. We noticed a drop in water pressure in the house, the hot water in particular. I have done a little research and l guess it could be the pressure relief valve going bad. But it seems coincidental that that would go bad now. Since we had to replace the shut off valve, we had to shut off the main. Would that have disrupted the prv, causing it to go bad? Or could it be the water main valve itself since it has only been turned a handle full of time since 1986?