What Causes Low Water Pressure in Kitchen Sink?

Low water pressure in the kitchen sink is a common headache for many homeowners.

Imagine having a sink full of dirty dishes and turning on the faucet only to find out dripping water. Several issues may cause this frustrating scenario.

We will discuss all these issues in this article to diagnose the source of the problem and help you determine a good time to call a professional plumbing service.

The most common causes of low water pressure in the kitchen sink include damaged or clogged water lines, clogged aerators or cartridges, leaks, impaired shut-off valves or PRVs, and waterline interruptions.

The Causes of Low Water Pressure in Kitchen Sink and How to Fix Them

This section will take a deeper look at what causes low water pressure in the kitchen sink.

We will also discuss DIY ways to fix these issues before you call a professional plumbing service.  

1. Broken Water Lines

When your water supply lines break, get damaged or clog up, water pressure problems can arise.

If broken water lines are the reason behind low water pressure in the kitchen, you might notice the same issue in bathrooms and other faucets around your house.

While water lines can break from time to time, detecting this issue is not an easy task. You can check if there is a break somewhere in your water lines by taking meter readings.

To do this, turn off all the water faucets and outlets around your home and take the meter reading. After about three to four hours, take another meter reading.

If you notice a change between the two readings, you probably have damaged or broken water lines. Call a professional plumber to come and take a look.

2. Aerator Clogs

An aerator is a small device found near the tip of the faucet. It controls the water flow rate.

Minerals, particles, dirt, or debris may clog up the aerator sometimes. With time, this gunk can build up and reduce the water pressure in the aerator.

A clogged-up aerator will cause your kitchen faucet to lose water pressure. In most cases, cleaning the aerator usually restores the water pressure issue.

All you need to do is separate the aerator by twisting it in a counterclockwise direction.  You can also use a set of pliers to get a better grip.

Once you have removed the aerator, soak it up overnight in vinegar and brush off the sediments.

All dirt particles should come off smoothly, but you can always get a new aerator if they are too stubborn.

3. Cartridge Clogs

Just like a clogged aerator, a clogged faucet cartridge could also be the reason behind the low water pressure in your kitchen.

A cartridge in the kitchen faucet is responsible for controlling the water flow.

When you twist the handle or lift the latch of your faucet, the cartridge opens the valves and allows the water to flow.

Cleaning a clogged-up cartridge is not as easy as cleaning the aerator. Let’s look at what you need to do in such a situation:

Before you dismantle your faucet, close the shut-off valve and let all the water flow out. Doing so will guarantee no extra water remains in the supply line.

Next, close the stopper in the sink so that no dirt or sediments escape into the drainage system.

Then, pry off the handle cap of the faucet using a screwdriver and use a pair of pliers to remove the retaining nut.

After you’re done, use a pair of pliers to remove the retaining clip and pull out the cartridge from the opening.

Clean the cartridge by dipping it in a bowl full of vinegar overnight. Rub off the sediments with a hard-bristled brush. If the gunk is too stubborn to come off, simply replace the cartridge.

4. Leaky Pipes and Toilets

If there is a leak in the pipe supplying water to your kitchen faucet, you might experience water pressure problems in your sink.

Even leaky toilets in your home can cause low water pressure in the kitchen sink and other areas around the home. A break in the water supply line or a toilet tank might be the reason behind the leak.

Sometimes, a stuck or warped flapper, faulty connection, fill valve or float might cause the leak. Although you can fix these problems by yourself, we suggest calling a certified plumber for expertise.

5. Shut-off Valve Errors

A shut-off valve is a component of a sink that cuts water flow to that specific fixture. Every sink in your home has a shut-off valve, usually located underneath or behind the sink.

Malfunctions in the shut-off valve can also cause low water pressure issues. If the valve has accidentally been moved into a more closed position, you might experience water pressure problems.

Since the shut-off valve remains non-functional most of the time, mineral sediments build up with time. This build-up can also cause water pressure problems.

Before you attempt to dismantle and fix the valve, ensure that it is completely open. If your sink has two shut-off valves for hot and cold water, examine both to see if they need a replacement.

You can easily replace the shut-off valve at home. To do this, close the main water line so that the water does not disrupt your work.

Then, remove the water line connected to the shut-off valve using a wrench to loosen the nut. Turn it in a counterclockwise direction.

Next, remove the compression nut that secures the shut-off valve in place. This will make the shut-off valve come off.

Have an identical shut-off valve at hand to replace the one you remove.

Once you have positioned the new shut-off valve in place, just tighten the compression nut to secure it. We suggest you don’t tighten the valve too much or you might damage the nut or the pipe.

Finally, reconnect the water supply line and check if the water pressure issue has been fixed.

6. Impaired Pressure Reducing Valve (PRV)

Many modern homes come equipped with a pressure-reducing valve (PRV). This device regulates the pressure coming from the municipal water supply into your home.

You can easily locate the PRV in your kitchen. Just look for a bell-shaped fixture sitting on top of the incoming water line.

If you are experiencing low water pressure issues in your kitchen, adjust the PRV by loosening the screw attached to its top. Turn it in the counterclockwise direction.

Then, open your tap again to see if there’s been an improvement in the water pressure level.

If it is still low, the PRV might be worn out. Call a professional plumbing service to come and take a look.

7. Waterline Interruption

Lastly, an interruption in your water supply line could also be a major cause of low water pressure. Detecting this interruption is not an easy task.

If you notice low water pressure in places other than your kitchen sink, there is likely an interruption in your water supply line.

You can confirm if there is an interruption in the water supply line by reading the meter reading. Earlier we discussed how you can do this. A change in reading can indicate a leak in the water supply line.

If the water line may be interrupted, you should call a professional plumber for an inspection.

Finding the Source of Low Water Pressure in Your Kitchen Faucet

Now that you know what causes low water pressure in a kitchen sink, you can easily find the source of low water pressure in your kitchen faucets.

The following checklist will help you find the source of low water pressure in your kitchen sink.

And who knows – maybe with a little grease and twists, you can solve the issue without the help of a professional!

  • Turn on every water source around your home individually. If every other faucet has adequate water pressure, you know the problem is just in your kitchen.
  •  Call a neighbor to check if they are having issues with water pressure. If they are, your municipal water supply is the likely culprit. You should contact your water provider right away.
  • Find out if the water pressure is low in both hot and cold water. If the pressure problem is only with hot water in your home, then there may be an issue with your water heater.
  • Thoroughly check all plumbing fixtures under and around your kitchen sink. If you notice dripping or standing water, call a plumbing service for a quick solution.

Frequently Asked Questions

Why is the water pressure only low in the kitchen sink?

The water pressure may be low only in the kitchen sink due to a clogged aerator or cartridge. The aerator is a small device attached to the end of the faucet that can accumulate mineral deposits or sediment, obstructing the flow of water.

Similarly, the cartridge inside the faucet can also get clogged by deposits or debris.

How can I fix low hot water pressure in the kitchen?

To fix low hot water pressure in the kitchen, you can try the following steps:

  1. Check the aerator: remove, clean, and replace it if it’s clogged.
  2. Inspect the cartridge: if it’s dirty or damaged, soak it in vinegar or replace it.
  3. Examine the hot water shut-off valve: ensure it’s fully open for proper flow.
  4. Inspect hot water heater: its settings, internal parts, and connections might need adjustments or maintenance.

What might cause low pressure after replacing a kitchen faucet?

Low pressure after replacing a kitchen faucet can be caused by incorrect installation, a damaged cartridge, or an obstructed water line.

Make sure the shut-off valves are fully open, and check for debris or blockages in the faucet connections.

Why is low water pressure affecting my kitchen sink and dishwasher?

If both your kitchen sink and dishwasher are experiencing low water pressure, it could be due to a shared water line issue or sediment buildup in the pipes.

A professional plumber may be needed to diagnose and resolve the problem.

How does a clogged aerator affect water pressure?

A clogged aerator affects water pressure by reducing the flow of water through the faucet.

When mineral deposits or debris accumulate in the aerator, it obstructs the passage, causing the water to flow out at a reduced rate and pressure.

What could cause a sudden drop in water pressure in the sink?

A sudden drop in water pressure in the sink could be caused by various factors, such as:

  • A burst or leaking water pipe
  • An issue with the water supply or shut-off valve
  • Blocked or damaged plumbing fixtures
  • Significant usage of water in other parts of the house

In such cases, it’s advisable to consult a professional plumber to find the root cause and necessary repair.

Final Words

Trying to fix low water pressure problems can take a lot of trial and error. You can try and fix these issues on your own as we discussed above.

However, if you don’t want to spend your precious free time and energy trying to diagnose the problem, contact a licensed plumber.

A licensed plumber will be able to diagnose the problem and then quickly get to work on resolving your low water pressure issue.

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