Bad water pressure in home - cause and solution?

Question

Lately the water pressure in our house has been really poor, especially upstairs (but also downstairs). It seems to have happened all of a sudden -- if something someone in our home did to cause it, we have no idea what. It is especially bad when two water sources are running at the same time -- for example, today someone flushed the downstairs toilet and I turned on the upstairs faucet while the toilet was still filling. Almost no water came out of the faucet (I had both hot and cold turned all the way on) until the downstairs toilet stopped filling. Then the water pressure got better, but still wasn't what it should normally be.

Any ideas of what might be causing our bad water pressure and how to go about fixing it? It's really annoying when you're trying to take a quick shower but don't have enough pressure to wash all the soap off quickly!

Answer 1

With water "pressure" there is two issues. One is pressure (static) and the other is flow.

Static pressure is the pressure when nothing is running. If you measure it with everything off that tells you the pressure coming in to the house past your regulator, if you have one.

If the pressure is okay with no water being used then check it with water running. If it falls off (as it sounds from your description) then you have a flow problem, a restriction.

"IF" you have a pressure regulator it might be bad. Sometimes you can free them up by tapping on them but it still needs to be replaced. They also sometimes have a screen in them that might be clogged from junk in the water from construction nearby. If not the regulator then you get in to other restrictions like a valve on the incoming water not fully open or rusted pipes.

Since you said it happened suddenly it is most likely the regulator is not opening up when the pressure drops as water is being used.

Not all homes have them but most do.

Good Luck.  

Answer 2

Try to isolate the problem either in your home or outside, ask your neighbors on each side of you if their water pressure has also dropped. If so the it's a call to the city or the county. Pressure should be at least 40lbs per sq in coming into your home. It's possible there might be construction somewhere close to you.

Answer 3

It sounds like the sudden onset of your water pressure dropping is because your supply lines are clogged up with tuberculation which builds up over time to the point where it becomes a problem (see http://curaflo.com/CuraFlo/AboutPipeProb... for photos and more information about tuberculation). It might also be that your lines are undersized.

Only so much water is in your supply lines at any time, and that gets divided up by the number of fixtures you have. So for example, if you only have the showing running, all the pressure and flow is in one direction. But if someone then opens a faucet, your water supply and its pressure are now divided.

I'd first recommend trying to increase your pressure by adjusting your PRV (pressure reducing valve), but if that doesn't work I'd recommend epoxy lining or repipe (replacing your pipe).

Answer 4

The fact that it happened all the sudden is cause for optimism.  It could be a valve that isn't opened all the way, or a chunk of debris blocking the flow somewhere.  If you're on a well, there may be equipment failure.

You'll probably need to get a plumber on-site to figure it out, but it doesn't sound like you need a re-pipe.

Answer 5

You didn't mention if you had city water or well water. It makes a big difference.

Answer 6

If you are in an area where building is going on, or city-wide repairs, sometimes water usage by the municipality can cause a loss of pressure, and volume.

Another great suggestion is to make sure you are the only one in your neighborhood.  Find out if others are experiencing the same problem.

You mentioned an acute drop in pressure, so it only leaves a few choices, besides the above.

As said before, a well pump problem, or a clog somewhere.

Finally, if your main valve is exposed (here in CA they are usually at the front yard hose-bib) , verify that someone didn't shut it off, or almost off.

Answer 7

The problem is most likely corrosion if you have old steel pipes. These pipes corrode from the inside out, and as they do the pipes narrow and the water pressure slows. This happens more quickly to hot water pipes than cold water pipes. Unfortunately, the only way to fix it is to replace the pipes.

Another very slight possibility is that the dip tube from your water heater broke and is clogging the shower head and faucets. If you have noticed that your hot water doesn't seem to last long, take the screen off of a faucet and look for white flakes. If there are some, call a plumber and tell him/her that you have dip tube failure in your water heater. Or get a new water heater, since it's probably about 15 years old anyways if you're having this problem. In the meantime, remove the shower head and faucet screens and clean out the white flakes.

If you're on a well, the problem could also be with the well pump.