How to Troubleshoot Low Water Pressure

Low water pressure can make all sorts of little tasks, from taking a shower to washing the dishes, less efficient (not to mention less pleasant). Inadequate pressure at a faucet may result from clogs and corrosion in pipes and in-line devices, or from low water volume or delivery pressure. Only after determining the cause can you and your plumber evaluate the solutions. Here's a diagnostic guide.

Difficulty: Moderately Challenging

Instructions

1. If the problem is limited to a fixture, try unscrewing any in-line device, such as a faucet aerator or showerhead, by hand or with pliers, and rinsing off or replacing clogged or corroded screens and parts on an in-line device such as a faucet aerator or showerhead.

2. If the problem is that the supply lines feeding a branch (say, in an addition) are too small, increase their pipe size.

3. If the problem is inadequate flow to the entire house, as might occur when you add new fixtures to an existing system, increase the size of the main supply pipe from the water meter to the house.

4. If the problem is inadequate pressure--for example, at the end of a municipal system or from a well located downhill--install a booster pump.

Tips & Warnings

• Soak showerheads in a vinegar-and-water solution to dissolve mineral deposits.
• When you install an irrigation system that includes backflow prevention in an existing home, you may see a significant loss of water pressure.
• Water pipes made of galvanized steel, found in some very old homes, become clogged over time. Replacement is the only effective solution.

[mariapdasilva]

on 5/28/2009 My toilet has low water pressure. What can I do to troubleshoot issue?

[thunderny]

on 8/12/2008 We have low water pressure at our outside faucets. When we turn on the faucet to use the hose(s), there is a "whining" noise we hear coming from the water lines under the house. We get low pressure from the spray nozzles on the hoses. How can we check and fix this solution and/or boost it? The pressure in the house seems normal. The showers could use more pressure but that is probably from the shower heads.

[BJJJ]

on 7/1/2008 To MsFixIt; Did you get a reply to this question below. I have the same problem BJ

on 1/9/2008 My water pressure problem occurs when I flush a toilet while the shower or sink faucet is running. The shower or sink water pressure goes down to a trickle. As soon as the toilet tank refills, the pressure is restored in the sink/shower. Where do I begin to solve this?

[dieseldoug]

on 2/7/2008 LISAINCT64, have your plumber check the dip tube on your water heater. This carries the cold incoming water to the bottom of the heating vessel to be heated. If it's broken, you will lose hot water rapidly during use as the incoming cold water dilutes the hot water at the top of the vessel. The good news is: it's a very cheap repair (a new dip tube is only about $4.00 at a hardware store). As far as your kitchen faucet is concerned, I think you have an obstruction in your faucet, despite what your plumber says. It's probably right in the supply lines just before the mixing valve on your faucet. That would account for the split second of normal water pressure you have followed by the weakened pressure.

[MsFixIt]

on 1/9/2008 My water pressure problem occurs when I flush a toilet while the shower or sink faucet is running. The shower or sink water pressure goes down to a trickle. As soon as the toilet tank refills, the pressure is restored in the sink/shower. Where do I begin to solve this?