To determine if your faucet is low-flow, you can measure its flow rate using the "bucket and stopwatch" method. Low-flow faucets generally produce 1.5 gallons per minute (GPM) or less, while standard faucets can flow up to 2.2 to 3.0 GPM.
A low-flow faucet is a water-saving fixture designed to reduce water consumption at the sink by restricting the maximum flow rate to 1.5 gallons per minute (GPM) or less, without sacrificing water pressure or everyday usability.
To increase a faucet flow rate, first unscrew the aerator at the tip of the faucet and soak it in white vinegar to clear trapped mineral scale or debris. If the flow remains weak, remove the internal flow restrictor or replace it with a higher-GPM version for maximum flow.
If only one faucet has low water pressure, the issue is isolated to that specific fixture rather than your home's main plumbing. The most common causes are a clogged aerator, a partially closed shutoff valve, or sediment trapped in the faucet's cartridge.
Faucets with rectangular aerators or open channel spouts typically have a flow restrictor under the sink. The screen at the spout does not restrict flow or catch debris.
Just take a can of WD-40 (preferably one with a long flexible hose) and spray it inside of your faucet. The WD-40 will loosen up the hard water and make the diverter work as smoothly as day one.
Slow Running Water
Turning on the faucet and getting a trickle of water is usually bad news. It can mean that there's ice on the inside wall of the pipe. Sometimes, you might turn on the faucet and get no water at all. During freezing temperatures, be aware of any sudden changes in water pressure.
To fix low water pressure in just one faucet, follow these steps in order of difficulty: clean or replace the aerator, ensure the shut-off valves are fully open, check for kinks in the supply lines, or replace the faucet cartridge.
A clogged P-trap typically announces itself through slow drainage, standing water, or gurgling noises as water attempts to pass through. To pinpoint the issue, try plunging the drain first. If it does not clear, you can manually inspect the U-shaped pipe under your sink.
Please keep in mind that all new faucets since 1994 are restricted to conserve water per EPA code mandates. Older faucets had no restrictions. Beyond intentional flow restriction, new installations can sometimes have reduced flow if the lines are not flushed prior to installation of aerators or shower heads.
If you've cleaned the aerator and the water flow is still weak, there may be a clog in the pipes. As time goes by, mineral deposits build up in your pipes. This will slow water flow and, eventually, may even cause your pipes to burst. Now is a good time to call in a professional plumber.
Standard modern showerheads use 2.5 gallons per minute (GPM), and some older showerheads use as much as 10 GPM. The Environmental Protection Agency (EPA) requires that showerheads use 2 GPM or less to warrant its WaterSense label and many low-flow showerheads are even more efficient, using 1.5 GPM or less.
For instance, issues like a clogged aerator, worn tap washer, or rusted internal components often block water flow at one faucet while other faucets work properly. Hard water buildup inside the faucet mechanism can also contribute to the problem, causing dripping or reduced flow.
Yes, you can adjust your home’s water pressure. This is done using your main Pressure Reducing Valve (PRV). The optimal water pressure for a home is between 404040 and 808080 PSI. Setting the pressure too high can damage pipes and appliances, while too low pressure will cause poor flow.
When only one faucet in your home has low water pressure, it is usually an isolated issue rather than a problem with your main water line. The most common causes are a clogged aerator, a partially closed shut-off valve, a blocked cartridge, or a kinked supply line.
Residential water pressure tends to range between 45 and 80 psi (pounds per square inch). Anything below 40 psi is considered low and anything below 30 psi is considered too low; the minimum pressure required by code is 20 psi . Pressures above 80 psi are too high.
Common Plumbing Issues that Cause Low Water Pressure
Over time, mineral deposits, rust, and other debris can build up inside your pipes and fixtures, causing blockages that restrict water flow. A plumber can help clean or replace clogged pipes and fixtures to restore proper water pressure.
In plumbing, the "135-degree rule" is a code standard that dictates how much a horizontal drain pipe can bend or change direction. It limits the total cumulative angle of pipe fittings before a system requires an access point (cleanout) or must be vented, ensuring proper flow and preventing chronic clogs.
A slow, steady drip can help prevent frozen (and burst) pipes during cold weather.
The best way to remove hard water stains from faucets and fixtures is to use white vinegar, which dissolves mineral buildup without damaging most finishes. Simply soak a cloth or paper towel in vinegar, wrap it around the affected area, and let it sit for 15–30 minutes.
Bathrooms are naturally humid spaces, and over time that moisture can contribute to rust and corrosion on faucets and shower heads. Using WD-40® Multi-Use Formula helps protect these fixtures by creating a light barrier that supports regular upkeep in damp environments.
While WD-40 is a great multipurpose solvent, it is a poor long-term lubricant and should never be used on items that require specialized lubricants, come into contact with food, or are made of sensitive plastics and rubber.