Why is My Kitchen Faucet Leaking Under the Sink

A leaking kitchen faucet under the sink can be a perplexing and frustrating problem. This issue not only wastes water but can also lead to more significant damage to your cabinetry, flooring, and even the structural integrity of your home if left unaddressed. Why is my kitchen faucet leaking under the sink? Here are some common reasons why your kitchen faucet might be leaking under the sink and what you can do about it.

Why is My Kitchen Faucet Leaking Under the Sink

1. Loose or Damaged Connections

Problem: The connections where the faucet attaches to the water supply lines might be loose or damaged. Over time, the nuts and bolts that secure these connections can loosen due to vibrations and regular use. Additionally, if the connections were not installed properly initially, they might leak from the get-go.

Solution:

• Tighten the Connections: Use a wrench to carefully tighten the nuts and bolts securing the faucet to the supply lines. Be cautious not to over-tighten, as this can damage the fittings.
• Inspect for Damage: Check the connections for any visible signs of wear or damage. If you find cracks or corrosion, replacing the affected parts may be necessary.

2. Worn-Out O-Rings and Washers

Problem: O-rings and washers are small rubber components that create watertight seals within the faucet assembly. Over time, these parts can become brittle, crack, or wear out, leading to leaks.

Solution:

• Replace O-Rings and Washers: Turn off the water supply to the faucet, disassemble the faucet, and replace any worn-out O-rings and washers. These parts are inexpensive and can be found at most hardware stores.

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3. Faulty Cartridge

Problem: Moen faucets, like many modern faucets, use a cartridge to control the flow and temperature of the water. A faulty or damaged cartridge can cause leaks both at the spout and underneath the sink.

Solution:

• Replace the Cartridge: Shut off the water supply, disassemble the faucet, and replace the cartridge. Make sure to get the correct cartridge for your faucet model. Moen provides lifetime warranties on many of their parts, so you may be able to get a replacement cartridge for free.

4. Corroded Valve Seats

Problem: The valve seat connects the faucet to the spout. Over time, water sediments can cause the valve seat to corrode, leading to leaks.

Solution:

• Clean or Replace the Valve Seat: Remove the faucet and clean the valve seat with a seat wrench and a cloth. If the seat is too corroded, it will need to be replaced.

5. Cracked or Damaged Faucet Body

Problem: The body of the faucet itself can develop cracks or other damage over time, especially if it’s made of lower-quality materials or if it has been subjected to excessive force.

Solution:

• Inspect and Replace: Examine the faucet body for any visible cracks or damage. If you find any, you may need to replace the entire faucet. Moen faucets are known for their durability, but even high-quality fixtures can develop issues with age.

6. Water Supply Line Issues

Problem: The supply lines themselves can be a source of leaks. These lines can develop cracks, or the connections can become loose over time.

Solution:

• Inspect the Supply Lines: Check the supply lines for any signs of wear, such as cracks or bulges. Ensure the connections to both the faucet and the water supply are tight. If the lines are damaged, replace them with new ones.

Preventative Measures

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Preventing leaks under your kitchen sink involves regular maintenance and prompt attention to any small issues before they become big problems.

• Regular Inspections: Periodically check under your sink for any signs of moisture or leaks. Addressing small drips early can prevent major issues.
• Proper Installation: Ensure that your faucet and supply lines are installed correctly. If you’re not confident in your DIY skills, it might be worth hiring a professional.
• Use Quality Parts: When replacing parts, use high-quality components. Cheaper parts might save you money upfront but could lead to more frequent repairs and replacements.
• Keep it Clean: Regularly clean your faucet and its components to prevent sediment build-up, which can lead to corrosion and leaks.

Conclusion

A leaking kitchen faucet under the sink can stem from several causes, ranging from simple loose connections to more complex issues like a faulty cartridge or corroded valve seats. By understanding these potential problems and knowing how to address them, you can maintain a leak-free kitchen and avoid costly water damage. Regular maintenance and timely repairs are key to keeping your Moen faucet, and any other faucet, functioning efficiently for years to come.