Why Is My Coffee Maker Leaking? (Causes and Fixes)

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You press brew, walk away, and come back to a puddle on the counter. A leaking coffee maker is annoying, but in most cases the cause is simple and you can fix it in a few minutes without buying anything. This guide shows you where the water is coming from, what usually causes it, and how to fix each problem. If the machine is past saving, we also point you to replacements.

Why Is My Coffee Maker Leaking? (Causes and Fixes)

How we put this together: we did not lab-test a leaking machine for this article. The advice comes from manufacturer manuals, retailer troubleshooting guides, and recurring owner-reported problems, combined with what we already cover in our guide on how drip coffee makers work.

Quick Answer: The Most Common Reasons a Coffee Maker Leaks

Most leaks come down to one of these: the water tank was overfilled, the filter basket overflowed, the carafe isn't seated correctly, a seal is worn, or limescale is blocking the water path. Start by working out where the water appears, since that points you to the cause.

Where the water appears	Most likely cause	First thing to try
Around the filter basket	Basket overflow, too-fine grind, folded filter	Use the right filter size and a medium grind
Under the machine	Overfilled tank, cracked tank, worn seal	Fill only to the line, then inspect the tank
At the carafe or lid	Carafe not seated, cracked carafe, dirty drip-stop	Reseat the carafe and clean the lid
Slow drip with puddles after brewing	Limescale buildup	Descale with vinegar and water
From inside the base while brewing	Cracked internal hose or failed seal	Stop using it and check the warranty

Before You Start: Safety

Unplug the machine and let it cool before you inspect anything. Water plus electricity is a real hazard, so if you find water inside the base or around the cord, don't plug it back in until everything is completely dry.

8 Causes of a Leaking Coffee Maker (and How to Fix Each One)

1. You Overfilled the Water Tank

It sounds obvious, but this is the most common cause. If the water level goes past the max line, the extra water can spill out of the reservoir or push through the machine faster than the basket can handle.

Fix: fill to the line for the number of cups you want, not to the top. If you use the carafe to fill the tank, check that it isn't a different size from the one that came with the machine.

2. The Filter Basket Is Overflowing

If water pours over the sides of the basket, the grounds are blocking the flow. The usual culprits are coffee ground too fine, too many grounds, or a filter that has folded over on itself.

Fix:

• Use a medium grind, about the texture of sea salt.
• Don't heap the grounds above the recommended dose.
• Make sure the filter is fully opened and sits flat in the basket.
• Use the correct filter size. Cone machines like the OXO take #4 cone filters, and a wrong size is a common cause of overflow.

A filter that fits properly is the cheapest fix for overflow leaks:

3. The Carafe Isn't Seated Correctly

If the carafe is slightly off-center, brewed coffee can miss the opening and run down the outside. Machines with a pause-and-serve valve also depend on the carafe pressing the valve open.

Fix: place the carafe squarely on the plate and push until it sits fully in position. Check that the lid is on correctly, because a loose lid sends the stream sideways.

4. The Carafe or Lid Is Cracked

A hairline crack in a glass carafe can seep water you won't notice until it's on the counter. Thermal carafes can also leak if the seal inside the lid wears out.

Fix: hold the carafe up to the light and look for cracks. Check the lid gasket for tears or hardening. If either is damaged, replace the part. Don't keep using a cracked glass carafe on a hot plate.

If your glass carafe is cracked and the machine is already a few years old, a replacement with a thermal carafe is one option:

5. Limescale Is Blocking the Water Path

Mineral buildup narrows the tubes inside the machine. Water slows down, backs up, and finds the easiest place to escape, usually around the basket or under the unit. Scale is also the number one reason cheap machines die early, as we mention in our best coffee makers under $100 guide.

Fix: descale the machine (steps below). If your brew is also unusually slow, our article on why a coffee maker takes so long to brew covers the same buildup problem from another angle.

6. The Drip-Stop or Pause-and-Serve Valve Is Dirty

The small valve under the basket stops coffee from dripping when you pull the carafe out. Coffee oils and grounds can stop it from closing, so it drips onto the hot plate.

Fix: remove the basket, rinse the valve area with warm water, and wipe away any grounds or residue. Run a plain-water cycle afterward.

7. Worn Seals, Gaskets, or a Cracked Water Tank

Rubber seals harden over time. A cracked reservoir will leak from the bottom, especially if it's been dropped or knocked around while being filled.

Fix: if the tank is removable, take it out and check for cracks and for a worn rubber ring where it connects to the base. Many manufacturers sell replacement tanks and gaskets. If your machine has a fixed tank (like the OXO Brew 9-Cup), a leak from the tank usually means a warranty claim instead of a DIY repair.

If a leaking fixed tank has you shopping for a new machine and you brew full pots, this is the upgrade we've reviewed:

8. An Internal Hose or Connection Has Failed

If water appears under the machine while it's brewing and you can't find a problem with the tank or basket, an internal tube may have cracked or come loose.

Fix: stop using the machine. Opening the base yourself can void the warranty and is risky. Check your warranty period (OXO, for example, covers manufacturing defects for 2 years), keep your receipt, and contact the manufacturer.

If the leak is internal and the machine is done, and your household drinks different amounts of coffee, consider a two-reservoir brewer:

How to Descale a Leaking Coffee Maker

1. Empty the carafe and basket and discard any grounds and filters.
2. Fill the tank with half white vinegar and half water. Check your manual first, since some brands recommend their own descaler.
3. Start a full brew cycle. If your machine allows it, pause halfway for about 30 minutes so the solution can sit.
4. Finish the cycle, then pour out the vinegar mixture.
5. Run two full cycles of plain water to flush out the vinegar taste.

Descale every 1 to 3 months if you have hard water, and about every few months otherwise. For more on how water moves through a drip machine, see our guide to how drip coffee makers work.

Quick Test to Find the Leak

1. Unplug the machine, dry the counter, and place a dry paper towel underneath.
2. Fill the tank to the line with plain water and set a clean carafe in place.
3. Run a cycle without coffee and watch where the first drops of water appear.
4. If the towel stays dry but water shows up at the basket, the cause is the filter, grind, or scale. If the towel gets wet from underneath, check the tank and seals.

Should You Repair It or Replace It?

Repair or keep it if: the leak came from overfilling, a wrong filter, a dirty valve, or scale. Those are all free to fix.

Replace it if:

• The leak is inside the base or from a cracked tank on a fixed-tank machine.
• It keeps leaking after descaling and a clean basket.
• The machine is several years old and the replacement parts cost close to a new unit. Our under $100 roundup says budget machines tend to last roughly 2 to 4 years with regular descaling.

Not sure what to buy? This is our default pick for most kitchens:

How to Prevent Your Coffee Maker From Leaking Again

• Fill to the line, never to the brim.
• Use the right filter and grind. Medium grind, correct size, fully opened.
• Descale on a schedule, especially in hard-water areas.
• Wash the basket, valve, and carafe lid regularly so oils and grounds don't build up.
• Check seals and the carafe every few months for cracks or hardening.
• Keep your receipt so you can claim the warranty if an internal part fails.

FAQ

Why is my coffee maker leaking from the bottom?
The usual causes are an overfilled tank, a cracked reservoir, a worn seal, or an internal hose problem. Unplug it, dry everything, and run a plain-water test to see where the water appears first.

Why is my coffee maker leaking from the filter basket?
Overflow is the likely cause. The grind may be too fine, there may be too many grounds, or the filter may have collapsed. Switch to a medium grind and the correct filter size.

Can a clogged coffee maker leak?
Yes. Limescale narrows the internal tubes, which slows the flow and can force water out around the basket or the base. Descaling often solves it.

Is it safe to use a leaking coffee maker?
Not if water is getting into the base or around the cord. Unplug it and let it dry fully. If it leaks from inside the machine, stop using it and contact the manufacturer.

How often should I descale my coffee maker?
Every 1 to 3 months is a common recommendation, but follow your manual and descale more often if you have hard water.

Is it worth fixing a leaking coffee maker?
If the cause is overfilling, a wrong filter, a dirty valve, or scale, yes, since those cost nothing. If the leak is internal or the unit is several years old, a replacement is usually the better value. Browse our best coffee makers under $100 to compare options.

Final Thoughts

Most leaking coffee makers aren't broken. They're overfilled, clogged with scale, or using the wrong filter. Work through the causes in order, run the plain-water test, and descale before you give up on the machine. If the leak is coming from inside the base, replace the unit or use your warranty, and pick a replacement that fits how you really drink coffee.

Last updated: November 11, 2026. Prices and availability change, so confirm details on Amazon before you buy.