In my house I have a water pressure issue:

  • Pressure is fine everywhere except for the hot water supply to the second floor shower
  • There is another shower in the basement that has good water pressure
  • The water heater is also in the basement
  • Both lines to the shower are copper

The issue is not with the shower head as the hot water pressure is also very low out of the tub faucet compared to the cold pressure. I have disassembled and removed the entire faucet assembly including the cartridge, and when the water is turned back on pressure is low even directly from the pipe. The shut-off valves for hot and cold are fully open as far as I can tell.

So, what could be the issue? Could the hot water line only to that shower be blocked? How can I clear it?

1 Answer 1


I've had exactly this issue, on the hot line to a tub, and eventually (disassembling the piping as I went) found an elbow almost plugged with solder - a half-inch pipe with a 1/16" or smaller hole through the nearly-plugged fitting. Someone got over-entusiastic feeding solder (probably 40 years ago for the one I found - and someone lived with the tub that way for probably 40 years, which is the puzzling part.)

So, 7 years later, I happened to have camera and the fitting in question from my junk (perhaps "plumbing trophies") box and recall that I want to show it. Trigger warning "terrible plumbing."

Copper pipe elbow plugged with solder - image by me

The little gap at the bottom of this picture was the only passage for water in this fitting.

  • 2
    Now that the issue's been resolved, I can say that this was the problem in this case as well- solder blocking the hot water line. Thanks! Oct 10, 2014 at 22:42
  • I had exactly this issue with the aerator screen (some small specs of solder) on only one faucet.I would have thought they would have traveled to the unit I turned on first - farthest away but nope it was the middle room. - I thought I was ok in my soldering but did have some areas that took a bit more surety to make sure I did not have any leaks. The first time I connected - I had a leak on the backside next to dry wall and with water in the line my propane torch just wasn't up to snuff - so I had to redo it. Guess a couple flakes spit through and did not stick.
    – Ken
    Nov 4, 2017 at 5:50

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