Leak Under Kitchen Sink (How to Locate & Fix It Fast) (2022)

Some leaks are easy to notice, and a leak under kitchen sink is one of them. The puddle of water that appeared on the bathroom floor isn’t easy to ignore.

However, just because the damage is in a noticeable place doesn’t mean you should let it be.

Any leak and plumbing issue can cause severe damage to the structure of your home. The worst part of it all is thatnot all the damage is covered by insurance.

This is why you should always know how to locate and fix a leak under kitchen sink. Some problems might even be resolved without calling a professional!

How to Locate a Leak under Kitchen Sink?

Leak Under Kitchen Sink (How to Locate & Fix It Fast) (1)

Before you learn how to fix a leak under the kitchen sink, you must know how to locate it. Here are the most common kinds of leaks:

  • Drain leak
  • Water supply leak
  • Faucet leak
  • Leaky P-Trap
  • Damaged washers
  • Broken reverse osmosis system
  • Clogged or damaged pipes
  • Garbage disposal clogged with food

Below, we have explained how to locate most of these leaks. We will also give you a few bits of advice on how to repair them – and if you can even do that by yourself.

Drain Leak

Leak Under Kitchen Sink (How to Locate & Fix It Fast) (2)

A drain leak is the most common one, and it’s fairly easy to locate. Turn the water on, then drain it out of your sink. If you notice any leaks while the water is draining, then this is causing the problem.

Chances are you have a drain blockage, or that something inside it is corroded or rusted.

Most sinks have a drain sealed with the help of a plumber’s putty. This putty prevents leaks, and it’s good to have it on.

(Video) How to Repair a Leak Under the Sink : Home Sweet Home Repair

However, as time passes, the putty can dry out. Sometimes, it was too thin, to begin with, and it simply couldn’t hold on that amount of water.

If any of these is the issue, we suggest calling a professional to help you out. Replacing a putty isn’t recommended, and you should instead remove the drain altogether.

Sometimes, the problem lies in loose nuts that are located on pipes’ meeting points. Make sure these nuts are tightened all the way before you assume anything else.

Loose nuts can cause serious leakage, but they are easy to fix. Don’t waste any money if you don’t have to.

Water Supply Leak

Water supply leaks are also a typical kind of damage to the kitchen sink. To locate it, do the same things as with drain leaks – let the water run and try to drain it.

If the water isn’t draining, but you notice a puddle appearing under the sink, then you have this problem. A faulty pipe or joint usually causes water supply leaks.

Another way to know you have a problem with a water supply is if the leaks are constant.

A kitchen sink typically has two water supply connections – one for cold water and one for warm water.

Sometimes, there is a third connection, as well, if your sink has a separately connected sprayer.

Any of these connections can break, corrode or rust, and cause water to drip.

These leaks usually go under the radar until they soak everything in the storage under the sink. This is because the connections are rarely in a visible place.

A failed connector gasket is also a common cause of a water supply leak under kitchen sink. If this is the case, replace the gasket.

This should prevent any further leaks. Sometimes you don’t even have to replace it – just make sure everything is tightened up.

(Video) QUICK TIP FOR A KITCHEN SINK DRAIN THAT IS LEAKING!

If the leaks keep on occurring, contact your local plumber. When the problem is in the corroded pipes, there isn’t much you can do otherwise.

Faucet Leak

You can usually spot this leak with no problems what so ever. If the puddle appears when you turn on the water, you can be sure this is the problem.

Sometimes, the leak can occur underneath the sink. You won’t be able to spot it without looking under the kitchen counter.

If the water runs from the faucet handle, you likely have some damage to the O-ring. The O-ring is a small disc affixed to the stem screw that keeps the faucet handle in one place.

This is one of the more common faucet leaks, especially if you have a cartridge faucet. The O-ring isn’t the most resilient part of the faucet.

It can easily become loose or worn out after a few years of using the sink. Luckily for you, replacing the O-ring isn’t difficult, and you can usually do it yourself.

The problem might also lie within the valve seat. This is usually the case if you notice leaks near the base of the faucet.

The valve seat connects the tap and the sprout, and it helps the compression mechanism. When the water accumulates in it, it can corrode and rust.

Over time, this causes enough damage for the faucet to start leaking. Sometimes, you can replace the valve seat by yourself, but it would be best to contact a professional.

Also, we’d advise you to call a plumber to clean the valve seat regularly. This can prolong the life of your kitchen sink.

Leaky P-Trap

Leak Under Kitchen Sink (How to Locate & Fix It Fast) (3)

Look under the kitchen counter where the sink is. Do you see the curved pipe section there? That is known as the P-trap.

(Video) Fixing a Leak Under the Kitchen Sink

It prevents bad smells from exiting the drain. If you notice bad smells together with the leak, this can be a telling sign that your P-trap is clogged.

Identifying this leak can be difficult, though, especially if it’s not followed with foul scent. This is because the P-trap is hidden from the eyes, so it’s not the first location we would think of.

The P-trap can get clogged over time, causing water to leak. The culprit behind this is usually disposed food, debris, and gunk.

All of these block the water drainage. Try unclogging it with chemicals or with a plunger. This may be enough to stop the leak.

Also, P-trap can rust over time, especially if it’s made of metal components. If this is what happened, you should replace it entirely.

Once again, this is a job for a professional plumber.

Damaged Washers

Another common reason behind a leak under the kitchen sink are worn-out or damaged washers. This is especially common with compression faucets. And yes, using a touchless faucet is a good choice.

Washers are rubber rings that press the valve seal every time you turn the tap on. They are under constant friction, and this can make them worn-out.

When this happens, you can easily see the leaks around the spout of the sink. You don’t have to call a professional to fix this problem. Simply replace the washers.

Make sure you have the replacement washers in the same size! If the new ones are too thin, the sink may leak again.

Broken Reverse Osmosis System

Reverse osmosis water filtration systems are an inexpensive way for you to have clean and fresh drinking water.

At the same time, they need a very low amount of maintenance, and you don’t need to give them constant attention. This is why many people have them installed in their kitchen.

(Video) Sink WON'T Stop Leaking | FAST REPAIR

However, even these systems can break, causing puddles on the kitchen floor and inside the cabinet.

To locate them, look for drips in hoses connecting the system to the sink. Another typical place to look for is a leak in the refrigerator’s water dispenser or your ice maker.

Clogged or Damaged Pipes

The most serious culprit behind a leak under the kitchen sink is your sewage system. Sewage pipes can last for a very long time.

Most of us will move out of the house before the lines get old enough to break. However, this can happen.

While it’s rare for clogged pipes to leak only under the kitchen sink, it’s possible. This is done when the water can’t go through the system, causing leaks.

Usually, this leak can be noticed on the wall behind the sink. If any water stains are appearing, pipes are the likely reason behind it.

Sadly, this problem can be expensive, and you should contact a professional for help. Don’t mess with pipes alone, as you can only increase the damage.

So what to do with the leak under kitchen sink?

While smaller leaks and dripping don’t look like a huge issue, you should never hesitate to fix it. Water can cause great damage both to your house and your health.

It can damage the home structure, ruin the walls or the flooring, or cause the parquet to rise.

Not just that, but water causes mold, which can be extremely damaging to your health. [2]

Leaks underneath the kitchen sink can be the sign that there is something severely wrong with the sewage system. If you leave them be, you are risking serious problems that will be ten times more expensive. [2]

When you aren’t sure what’s causing the leaks, don’t fear to contact a professional. Only this way you can be certain that you did your best to prevent further problems.

(Video) How to Replace A Kitchen Sink Drain Strainer, Repair Leak

FAQs

How do you find a leak under the kitchen sink? ›

Use the corner of your rag or paper towel to absorb any water in the nooks and crannies. During this process, you may get more evidence of where the leak is. If the leak is coming from one of the water lines or from up inside the faucet, you may notice a spot where water comes right back as soon as you dry it off.

How can you tell where a water leak is coming from? ›

How To: Find a Plumbing Leak
  • Monitor the Water Bill.
  • Watch the Water Meter.
  • Check for Patches of Greener Grass.
  • Investigate Appliances and Fixtures.
  • Dye Test the Toilet.
  • Stay Alert to Leaking Clues.
  • Leak Detectors Offer Immediate Notification.
22 Sept 2020

Where is the leak under the sink coming from? ›

Arguably the most common reason you'll find water beneath your sink is that your drain has a leak in it. Shifting plumbing lines, worn-out connections, or even pipe corrosion could cause fractures in the plumbing lines beneath your sink, which cause water that flows down your drain to slowly and steadily leak out.

What to do if you have a leak under your sink? ›

The main cause of an under sink pipe leaking are the fittings around shut off valves, so it should be a simple fix by tightening these up. You need to use a wrench the hold the valve while tightening the compression nut with your hand. Still leaking? Tighten the faucet connection.

How do you dry out under a sink? ›

How to Dry Up Water Under a Sink
  1. Clear Out the Space Under the Sink. Remove any items located under the sink and in close proximity to the pooling water. ...
  2. Soak Up the Water. ...
  3. Look for Signs of a Leak. ...
  4. Open the Cabinet Doors. ...
  5. Catch Any Leaks. ...
  6. Repair the Leaks. ...
  7. Look for Mold. ...
  8. Prevent Future Mold Growth.

How do I know if my pipes are leaking under my floor? ›

How to Find a Leak in Plumbing Pipes Under Floors : Plumbing Repair Tips

How do plumbers detect water leaks? ›

Ground microphones and listening discs are among the basic tools that plumbers use to pinpoint leaks. Using sound technology, they can hear the noise of escaping water and dripping even through a layer of concrete.

Is there a tool to detect water leak? ›

A water leak detector can reduce the risk by alerting you to problems quickly, so you can act to prevent severe damage. We've tested several over the past few months, and these are the smart water leak detectors we recommend.

How do you trace water pipes? ›

Today, the best tool for the job is ground penetrating radar (GPR) as it accurately maps metal and PVC pipes. Traditional pipe locators use electricity and magnets to locate underground pipes.

Why is my sink leaking at the base? ›

Temporary leaks occur when the sink is in use. These leaks are most prevalent in fixtures with dirty or worn-down O-rings, the seal at the faucet base. According to Fluid Power World, O-rings are the most common fluid power seals for preventing leaks. Constant leaks continue even when the sink is off.

Can a faucet cause a leak under the sink? ›

Faucet Leak

It is also possible for a faucet leak to run underneath the sink, which means you can only spot it if you look under the counter. In most situations, a faucet leak is caused by failed washers or worn-out gaskets. All you need to do is replace them.

How much does it cost to fix a leaking sink? ›

What affects the cost of sink and faucet repairs?
Sink Repair JobAverage Cost
Clearing and repairing pipes$120 - $170
Stopping a dripping faucet$65 - $150
Fixing sink surface problems$100 - $200
Replacing a sink or faucet (installation costs only)$150 - $400
1 more row
26 Aug 2020

What can I use to seal a leaky pipe? ›

To repair a leaking iron pipe: Apply epoxy directly onto the leaking pipe, like you would with caulk or plumber's putty. The epoxy will temporarily form a seal over the leak. To repair leaking PVC or copper pipes: Affix the pipe clamp or wrap around the leak.

How do you fix a hole in a pipe under the sink? ›

Answer: Two options for patching the hole in your drain trap are the Multi-Purpose Epoxy Putty, as you mentioned, and the Deluxe Pipe Patch Kit. Whether you use putty or a pipe patch will depend on how permanent you want to the solution to be. Putty is often used as a permanent solution.

How do I fix a leaky drain pipe? ›

How to Repair Cracked Drain Pipe [EASY] - YouTube

How do you dry out a flooded kitchen? ›

Set up fans in all four corners to create strong, fresh air cross-currents. A dehumidifier can help speed up the drying process too. Keep cabinet doors and drawers open, and pay special attention to damp drywall. If you're sure you don't have any mold problems in the kitchen, run the air conditioner.

How do I stop condensation under my kitchen sink? ›

The cure for condensation is actually very simple - adequate ventilation. OPEN the windows, especially wheh the tumble dryer is on.

How do I find a water leak under my tile? ›

8 tell-tale signs of a water leak
  1. Mouldy silicone.
  2. The odour of damp or mildew.
  3. Damp water marks in tiles.
  4. Deteriorating paint or wallpaper.
  5. Swelling or bubbling cabinetry or plaster.
  6. Missing grout in tiled surfaces.
  7. Damp carpet.
  8. Stained downstairs ceiling (under the room where the leak is)
11 Apr 2020

How do you tell if pipes are leaking behind a wall? ›

Signs of a Water Leak Behind a Wall
  1. There is mold or mildew in a non-shower area. ...
  2. There is peeling paint on the walls.
  3. The wallpaper is peeling.
  4. The bathroom has a water-stained or cracked ceiling.
  5. The flooring in the bathroom is buckled or cracked.
  6. There is a musty smell in a room that won't go away.
13 Mar 2018

How do I know if my concealed pipe is leaking? ›

Ultrasonic Leak Detector
  1. ultrasonic detectors are so sensitive that even blinking of the eye can also be picked up.
  2. big range of sound waves it can pick up – can be used in various conditions: pipes concealed in the wall, concrete floor, soil etc.
  3. high accuracy and can pinpoint exact spot of water leakage.

What to do if you think you have a water leak? ›

If you suspect a water leak in your home, the best way to tell is by checking the water meter. To accomplish this, first, turn off all the water to your home. Shut off any running faucets and be sure the dishwasher and washing machine are powered down, too. Then, watch the meter and note any changes.

Do small leaks seal themselves? ›

Sometimes a slow water leak can seal itself but don't rely on this happening. A slow water leak may seal itself if: The pipe swells under pressure. Metal oxidization causes micro expansion which may seal a leak.

How do you make a water sensor? ›

Simple Cheap DIY Water Sensor - YouTube

How much does a water leak detector cost? ›

Most water leak detectors cost less than $100 and can be installed by yourself, making them a very smart investment. A second type of water leak detector can not only detect a leak, but can also shut off the water coming into your home.

How much does it cost to install a water leak detection system? ›

Generally, whole house water leak detection systems take between four and six hours to install and cost between $500 to $1,500 depending on labor rates and the size of the system.

Can a metal detector find water pipes? ›

For example, using a pipe locator metal detector you can easily pinpoint leaking underground pipes quickly. You might also find the need to locate underground pipes and cables during a new construction project.

How do I find where my pipes are running? ›

Use a wall scanner. Use a stud finder to detect pipes while water is running through them.
...
Wall Scanner
  1. Use a pipe detector to find plastic water pipes in your wall.
  2. Run a nearby tap or shower so the wall scanner can detect pipes.
  3. Open both hot and cold taps to make sure all water lines are full and detectable.

How do you find a leak in a buried water line? ›

Look at your water meter for the leak indicator, which is often a small red, white, or blue triangle. The indicator spins when the house is using water. Because you shut off all water to the home, the triangle should be still. If it's spinning, you have a leak underground.

Why does my kitchen faucet leak around the base? ›

Leaks around the base of the spout are caused by worn O-rings located under the spout. All that's usually required to access these O-rings for replacement is to wiggle and pull up on the spout to remove it. Depending on the dripping faucet, you'll also have to remove the handle and other parts to access the spout.

Why is my kitchen sink pipe leaking? ›

Loose Compression Nut:

Likely the most common reason why your drain pipe is leaking at the connection. A loose compression nut will not seal the pipe correctly, so be sure to check the condition of the compression nut prior to scheduling a plumber to come out.

How do you seal a kitchen sink drain? ›

TIPS on using plumbers putty to seal kitchen sink basket - YouTube

Why does my sink leak only sometimes? ›

Leaks in a bathroom sink are frequently caused by clogged water supply lines, faulty p-traps, or poor sink drain pipe connections. Other reasons for bathroom sink leaks include blocked water supply pipes, incorrect p-traps, and poor sink drain connections; so double-check these areas.

What are the pipes under the sink called? ›

Trap: A P-trap is a two-part pipe under your sink that allows waste and water to pass through. The bend in the pipe prevents sewer gasses from entering.

What is plumbers putty good for? ›

Plumber's putty is a malleable, clay-like compound that creates a watertight seal by filling in the space under a flange to prevent water from seeping through. The product is ideal for setting faucets, sink basket strainers, shower and pop-up drains.

How much does it cost to fix a leaking pipe under sink? ›

Hiring a plumber costs between $125 to $350 for small repairs like unclogging a toilet or fixing a leaky faucet, while bigger plumbing problems cost $500 to $800 to fix on average.
...
Plumbing Repair Costs.
RepairAverage Cost
Main Water Line Leak$450 – $2,500
Cost to Repair Leaking Pipe in Ceiling$700 – $2,500
16 more rows

How much does it cost to replace a pipe under the sink? ›

The cost to replace all of the plumbing under your kitchen sink is between $100 and $350 on average. However, costs will be higher if you are adding a disposal, need to have a special drain hookup for a dishwasher, or an additional faucet hookup.

How much does it cost to fix a leak for a kitchen? ›

Leaking pipes cost an average of $150 to $350 to repair, while diagnosing leak locations can add an additional $100. This doesn't include repairing the wall after the fix. Drywall repair costs an additional $250 to $750 depending on the size and location of the hole.

How do you seal a leaking pipe faster? ›

How to Fix a Leaky Pipe | Plumbing | The Home Depot - YouTube

How do I fix a leaky pipe without replacing it? ›

How To Repair Leaky Pipes - Ace Hardware - YouTube

Is there a tape that stops water leaks? ›

Product Details. Rubber Flexx Waterproofing and Seam Tape is an easy to use peel and stick repair material to seal and fix leaks and problem areas. Ideal for use on roofs, gutters, skylights, windows, doors, flashings, walls, foundations and many other surfaces. Seals immediately to stop water and air leaks.

Does Flex seal work on water pipes? ›

Flex Tape is completely waterproof! It can cover gushing water from a hole in a bucket, and it can even be used under water to seal a leaking pool.

How do you fix a leaking PVC pipe without cutting it? ›

If you're dealing with a minor leak, rubber and silicone repair tape is a simple solution. Like fiberglass resin tape, rubber and silicone tape come in a roll that can be wrapped directly around the PVC pipe. However, instead of adhering to the pipe, the repair tape adheres directly to itself.

How do you stop a pinhole leak in a water pipe? ›

Because pinhole leaks are small, the easiest repair method is to fill them with epoxy putty. The best tool for the job is an epoxy putty stick, which combines the resin and the hardener in a pre-measured format. To use an epoxy putty stick, you tear off the amount of putty required and knead it by hand.

How do you find a leak under the kitchen sink? ›

Use the corner of your rag or paper towel to absorb any water in the nooks and crannies. During this process, you may get more evidence of where the leak is. If the leak is coming from one of the water lines or from up inside the faucet, you may notice a spot where water comes right back as soon as you dry it off.

What do most plumbers charge per hour? ›

The Cost of Hiring a Plumber

Typically, plumbers are subject to an hourly rate, which is often between $45 and $200. Common repairs attract an average rate of $120. Some plumbers prefer a flat rate estimate as the variables involved in plumbing repair make it hard to have an hourly rate.

What causes a kitchen faucet to leak at the base? ›

Dirt or debris have collected on the seals/o-rings/bearings which prevents the seals from making the faucet water-tight. The seals/o-rings/bearings are located in the faucet body. Continuous leak: This is characterized by a constant leak that occurs after the faucet is turned off.

Will a small water leak seal itself? ›

Sometimes a slow water leak can seal itself but don't rely on this happening. A slow water leak may seal itself if: The pipe swells under pressure. Metal oxidization causes micro expansion which may seal a leak.

How much does it cost to fix a leaky sink? ›

What affects the cost of sink and faucet repairs?
Sink Repair JobAverage Cost
Clearing and repairing pipes$120 - $170
Stopping a dripping faucet$65 - $150
Fixing sink surface problems$100 - $200
Replacing a sink or faucet (installation costs only)$150 - $400
1 more row
26 Aug 2020

Why is my kitchen sink dripping? ›

The typical causes for a leaky faucet include corrosion, mineral deposit on the internal parts, or defective gaskets, o-rings, or washers. Luckily, most faucets that leak can be fixed by homeowners if they have the right tools and some basic knowledge of plumbing.

How do I stop my faucet from leaking from the base? ›

If the faucet is leaking around the base of the faucet:
  1. If you have a single handle faucet (any style), remove and clean the aerator. ...
  2. If you have a two handle centerset faucet, remove and clean the aerator. ...
  3. If you have a two handle mini widespread faucet, you will need to replace the faucets O-rings.
13 Sept 2020

Why does my faucet drip after I turn it off? ›

If you notice your bathroom sink drips or leaks out of the faucet head when turned off, there is likely an issue with the seal inside the faucet head, allowing the water to run through or drip. Before calling a professional plumber, consider whether you're able to repair the leak in your bathroom sink yourself.

How do you seal the base of a kitchen faucet? ›

Roll a piece of plumber's putty between your hands until it forms a soft rope about 3/ inches thick. Apply a ring of putty to the bottom of the faucet base along the edges, using as much putty as needed to cover the entire edge of the base.

Does leak sealer work? ›

A leak sealant is simply a type of glue; think of it like wallpaper adhesive; the idea is that the leak drips out and is exposed to the air, then it sets. Rather than a repair, think of leak seal products like a plaster on a cut, it does not last, and unlike us, your pipes will not heal themselves.

Will silicone stop a leak? ›

Silicone would seem at first glance to be a good choice of sealant for leaks that might appear on the hull or deck of a boat. This is because silicone-based sealants have good properties, such as better chemical resistance and higher tensile strength than comparable polyurethane-based products.

How do you fix a leaking pipe without taking apart it? ›

How to Repair Cracked or Leaking Pipes Without Cutting or Threading

How much does it cost to replace a pipe under the sink? ›

The cost to replace all of the plumbing under your kitchen sink is between $100 and $350 on average. However, costs will be higher if you are adding a disposal, need to have a special drain hookup for a dishwasher, or an additional faucet hookup.

How do I know if my wall pipe is leaking? ›

Here are 5 signs you've got a hidden leaking pipe somewhere in your home.
  1. Outrageously high water bills. ...
  2. Water meter shows you've got a leak. ...
  3. Mold or mildew on non-shower walls. ...
  4. Stained, damaged, or sagging walls, ceilings and flooring. ...
  5. Musty smell.

Do plumbers charge for estimates? ›

Most professional plumbers offer clients a free estimate, which means they will come to your house, look at the job, and quote you an estimated cost. Don't let a plumber give you a price over the phone without looking at the repair first, because any estimate given this way will most likely be inaccurate.

How do you stop a leaking tap temporarily? ›

How to temporary fix a leak running down from your taps and onto the ...

What is plumbers putty good for? ›

Plumber's putty is a malleable, clay-like compound that creates a watertight seal by filling in the space under a flange to prevent water from seeping through. The product is ideal for setting faucets, sink basket strainers, shower and pop-up drains.

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