How to Fix a Dripping or Leaky Double-Handle Faucet
Determine which side of your faucet is leaking by shutting off the water supply valves one at a time. If the leak doesn’t stop after the first valve is turned off, it’s the other line that’s leaking.
Once you determine which side is leaking, turn off both supply valves.
If your valves are stuck, shut off the water main. You will have to replace hardware for both sides since you won’t be able to identify whether the hot or cold side is leaking.
Disassemble the Faucet
First, take the faucet apart.
Towel placed in sink basin to protect the finish and catch plumbing parts.
Turn faucet handles to the “on” position to release any residual water. Close the drain and place a towel in the sink to protect the surface and catch any dropped parts.
Vinegar soaked towel wrapped around aerator and secured with rubber band.
Remove the aerator and inspect it for damage. If it’s stuck, soak a towel in vinegar and wrap it around the aerator to help loosen mineral deposits. After an hour, gently twist the aerator with a towel and pliers.
Towel with organized faucet parts.
As you disassemble the old faucet, lay the parts in order on a flat surface and snap a picture for reference. Then, put those parts in a plastic bag and take them to the store with you when shopping. You may only require one part, but it may be best to buy a kit and replace everything, including a new aerator if yours is damaged.
How to fix a leaky cartridge faucet:
- Pry off the decorative cap on the handle, remove the handle screw, tilt the handle back, and pull it off.
- If there’s a threaded retaining clip holding the cartridge in place, use needle-nose pliers to remove it, then pull the cartridge straight up.
- Remove the spout and cut off the old O-rings using a utility knife. Coat the new O-rings with nontoxic, heat-proof plumber’s grease.
- To replace the entire cartridge, match the length of the old cartridge with the length of the replacement. Also match the stem end where the handle attaches.
Why Faucets Leak
All faucets work by controlling the flow of water through the use of an inner stem or cartridge with rubber or neoprene washers or seals that open and close against water inlet ports inside the faucet body. When these seals don’t properly fit, it allows a small amount of water to continue up to the faucet spout, where it creates that maddening and wasteful drip, drip, drip. The failure to seal can be caused by corrosion, by foreign material inside the faucet body, or (most often) by washers or seals that have lost their resiliency and are failing to seal properly.
There are some problems that can occur with any faucet type:
- Mineral (scale) buildup on the inner parts can cause any faucet to leak, since this mineral buildup interferes with the faucet’s ability to seal the water inlets. Here, you may be able to clean away scale and restore the faucet to good operating condition.
- Corrosion of parts within the body of the faucet. This can deform the water inlet ports to such a degree that the washers or seals on the faucet stem or cartridge can no longer seal properly and stop the flow of water. In this case, the practical solution is the replace the entire faucet, since repairs—even if they are possible—may not be cost-effective
- Leaking around the base of the spout is usually caused by worn O-rings around the body of the faucet underneath the spout assembly. This can occur with either cartridge faucets or traditional compression faucets.
Leaks Under the Sink
A leak under the faucet and sink can be the hardest to notice since most people don’t even look under the sink on a regular basis. This can actually be one of the most damaging leaks, though, since this water has nowhere to go but onto the floor. Left unrecognized, this kind of leak can damage the floor or your vanity or seep through the floor where it can cause very expensive damage.
Start by emptying out the sink vanity and thoroughly drying everything off. Next, run a bit of water to see where the leaking comes from. There are two likely sources of leaks under the sink:
- Water supply connections that are loose.
- Sink drain or P-trap connections that are loose.
These leaks can be very small, so if you can’t immediately see the source of the leaking, lay some dry paper towels on the floor or bottom of the vanity and check back in a day or so for water marks on the paper towels.
The water supply lines have three connections you should check: where the supply pipes connect to the shut-off valves; where the valves connect to the flexible supply tubes; and where those supply tubes connect to the tailpieces on the faucet itself. Any of these locations could be the place where water is leaking. It’s a matter of close inspection to identify the spot where the leak is occurring, then tightening the fittings to stop the leaking. In some instance, the shut-off valve or flexible supply tube may be worn out and need to be replaced.
It’s also possible, though less likely, that the faucet itself is worn out and needs to be replaced. In a very old faucet, the tailpieces may have corroded so far that tight connections to flexible supply tubes are no longer possible.
How to determine the cause of a leaky faucet
It’s best to always be vigilant of dripping faucets, as a single leaky fixture can waste 20 gallons of water a day! Give your sink a once-over to try to identify the source of the leak. If water is pooling around the stem of the faucet, you most likely need to replace the O-ring or tighten the packing nut.
If the leak is coming from the spout, there’s most likely a problem with the faucet handle. At this point, it’s helpful to have some knowledge about which type of faucet is in your home. The Spruce explained that a cartridge faucet is most common in modern homes, and you’ll typically need to replace the cartridge.
A compression faucet, on the other hand, is more typical in older homes. The rubber seals can wear out over time, so replacing them can usually remedy a dripping faucet.