When the water pressure at a single faucet is very low, the solution is often remarkably simple: an issue with the aerator.
What Is an Aerator?
An aerator is a screw-on screen fitting at the end of a faucet spout. The purpose of the aerator is to break up the solid stream of water and add air to the water flow—a function that can reduce water usage by as much as 30 percent.
When faucet aerators get clogged with grit or mineral buildup, they need to be cleaned to restore proper water flow. This is a common problem in regions where there is a heavy mineral content in the water supply.
Many people do not even know this fitting is there and often call a plumber to make a repair that is extremely easy. In most cases, a simple cleaning of the aerator will do the trick, though sometimes you may need to replace the aerator fitting. Usually, the aerator is screwed on tight and can simply be unscrewed and removed quite easily. In other cases, though, the buildup of mineral deposits may freeze up the aerator and make it hard to remove. In this case, applying heat and/or penetrating oil can help.
Equipment / Tools
- Channel-type pliers
- Rag or masking tape
- Hair dryer (as needed)
- Small stiff brush
- Penetrating oil (if needed)
- Lime-dissolving solution (if needed)
Attempt to Remove by Hand
Start by trying to unscrew the aerator from the spout by hand. Most faucet aerators have been threaded on by hand, and often you can unscrew it the same way. Make sure to dry off both the faucet and your hands first in order to get a good grip.
If removing by hand does not work, the next step is to try pliers. If the aerator is in good condition and you want to reuse it, wrap a rag or masking tape around the aerator to protect the metal surface against scratches before gripping it with the pliers. A small pair of channel-type pliers works best for this.
Grip the aerator between the jaws of the pliers, taking care to keep the jaws only on the aerator, not the faucet spout. Turn the aerator counter-clockwise (as viewed upward from below the spout) to unscrew it from the spout. If this does not work, try moving the pliers a quarter-turn around the aerator, and try unscrewing the aerator from the new position. (Moving to different positions can gradually loosen a stubborn aerator.) Take care not to grip the aerator too tightly, because the metal is soft and will bend easily, making your job even harder.
Aerators are sometimes thought to be "reverse-threaded," but in reality, it's just your perspective. When viewed from underneath the faucet, where the aerator is screwed in, the threading is normal (i.e., "righty-tighty, lefty-loosey." It's only when viewed from above that the threading appears to be reversed.
Heat the Aerator
When even the pliers don't easily remove the aerator, you can try applying gentle heat using a hairdryer, which may slightly expand the metal and make it possible to loosen it with pliers. Even a lit match held near the aerator may loosen the metal. Apply heat in moderation, though, as it is easy to melt any plastic parts or rubber washers if the aerator is overheated.
Cheaper faucets may actually use a plastic screw-on aerator—never use heat on plastic parts.
Apply Penetrating Oil
If heat also fails, try spraying penetrating oil (such as WD-40 or a similar product) on the threads and let it sit for a few minutes before trying again with pliers. Wipe off oil from the surface of the aerator before trying to unscrew it because oil makes the metal slippery.
Clean the Aerator
Once the aerator is removed, separate the parts and note their arrangement. There can be a surprising number of small parts within the aerator, and they must go back together in the same fashion in order to function correctly.
Use a small stiff brush to clean away any grit or mineral deposits from the screen and other parts of the aerator assembly. If there is a substantial amount of mineral buildup, soak the parts overnight in a lime-dissolving solution, such as Lime-Away.
Replace the Aerator if Necessary
If the metal screen or other parts are rusted or otherwise damaged, it is usually easiest just to buy a replacement aerator assembly. A variety of aerator heads are available, including swivel-head types that improve the functionality of the faucet.
Reassemble the Faucet
Reassemble the aerator, orienting the parts in the same way you found them when you removed it, and then screw it onto the faucet spout. Hand-tightening is usually sufficient, but if you notice leaking around the aerator threads when you test the faucet, tighten the aerator slightly more, using channel-type pliers.
The Big Benefits of Cleaning and Updating Faucet Aerators. City of Denver Water.