Occasional Low Water Pressure

[cptmullet]

Generally the water pressure for my shower is very strong, but every once in awhile the water pressure will drop. I know there are no leaks in the line and it's not because of too much draw on the water line system and it's not the shower head, I've checked for all these things. There have been a couple of times mid-shower that I've heard a slight popping noise and then all of a sudden the shower is no longer running at the same pressure. I believe it has something to do with the valve that switches the water from the bathtub to the shower or the piping on the way up to the shower head. I wanted to see if anybody might know the cause of the problem before I start opening up the shower. Thanks ahead of time!

 

[Jadnashua]

Most modern shower valves have what is called a pressure balance valve in them that will adjust if there is a momentary pressure drop. Sometimes, they can get sticky, so they do not restore the balance after say someone flushes a toilet. Most cannot be cleaned, but need to be replaced. Some are separate from the cartridge, some are inside of the cartridge.