Low Water Pressure In Your Bathroom Sink? 4 Causes And 8 Solutions

Low Water Pressure In Your Bathroom Sink? 4 Causes And 8 Solutions

Anthony Barnes

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Every time you get up in the morning and turn the faucet in your bathroom sink, you should expect a rush of water.

If that becomes a pitiful amount, it can prove difficult to brush your teeth, wash your face, and even your hands.

This is a problem you cannot leave so you should look to resolve it quickly. 

Thankfully, it can be simple to identify the problem and even fix it yourself with some typical household tools and a few rags or towels.

In this guide, we will look at how to isolate the problem with your bathroom sink, the causes of low water pressure in your bathroom sink, and how you can fix it. 

Isolate The Problem To Just Your Bathroom Sink 

If the low water pressure is simply attributed to your bathroom sink then you can focus on that appliance and it can prove straightforward.

However, if it is part of a bigger problem then you may want to contact a local, qualified plumber to check the entire water system.

There are various appliances to check which include the bathroom shower head, an en-suite sink, and a kitchen sink. 

The kitchen, and other rooms in your house, will use the same water system so if they also suffer from low water pressure then that can be quite troubling.

If it does prove to be more systemic then it does make sense to get a professional opinion from a local, qualified plumber. 

This overarching problem could be down to an intake valve that requires servicing or the feed pipes to your home need to be unclogged and cleaned.

Hopefully, after checking the other faucets and appliances, you can isolate the low water pressure problem just to your bathroom sink. 

The Causes Of Low Water Pressure In Your Bathroom Sink

Once you have isolated the low water pressure to solely your bathroom sink then you can do a few things about it.

This should not be a big job but you may need to set aside a few hours to do it properly and thoroughly.

The problem could be down to clogging, a flow restrictor working too well, poor installation and servicing, or water leaks and broken parts.

Clogging

There are several elements in a bathroom sink that can get clogged and result in low water pressure. These can include the water aerator and the water supply lines. 

The Water Aerator 

This tiny part can be found at the end of the faucet and features wire mesh.

The water aerator has two functions; the first is breaking up the water flow and aerating it (hence the name) for a steady, consistent water flow. 

The second function is to be used as a filter to collect any dirt or debris that may otherwise get into your water from your pipes.

As a filter, the water aerator can work well, almost too well as it creates an issue for the water pressure if it collects too much debris from the pipes which can restrict the water flow. 

You can either replace the water aerator or clean it yourself. For either method, you will have to unscrew the faucet and remove the water aerator. 

Clean The Water Aerator

You may see some large particles which are fine as it proves that the water aerator is doing its job by collecting them.

Rinse the water aerator under some running water and then scrub it with a stiff-bristle brush or old toothbrush until there is no more debris to clog it.

To do a full job, you can leave the water aerator to soak in some vinegar overnight to get rid of the mineral deposits that you cannot see. 

Replace The Water Aerator

For replacing the water aerator, take a note of the size and take it with you to a plumbing store so you can easily find the same one.

This is an option if simply cleaning the water aerator does not work and could prove successful in resolving the water pressure. 

You may want to get a few water aerators just in case you live in a hard water area which could mean that the water aerator is prone to clogging from mineral deposits.

The task of replacing the water aerator has already been done once so it should not prove difficult to do again. 

The Water Supply Lines

The Water Supply Lines

Just as you have cleaned and rinsed the water aerator, it is also possible that the water supply lines can be clogged too.

This can occur early on in a new build home as construction debris can get into the pipes to clog them up before water flows into them.

However, the water supply lines can also prove problematic in hard water areas, particularly for older homes as mineral deposits can build up and cause clogging which then results in low water pressure. 

Flush The Water Supply Lines

The water supply lines can be unclogged by flushing them out which may increase the water pressure once they are attached back in place.

Start closing the water supply valves by turning them clockwise until they are reassuringly tight. 

Next, release the remaining water by opening the hot and cold water faucets.

There may still be some remaining water and you can use a wrench to release it from the water supply lines underneath the faucet, use a bucket to catch the water as it flows out of the ends. 

One at a time, open the water supply valves then let them run for around ten seconds as the water flows into the bucket, and turn them off.

Grab the ends of the water supply lines from the bucket and return them underneath the faucet. 

Now the water supply valves can be turned back on and you can test the water pressure to check if the problem has been resolved. 

Clean The Water Supply Lines

If flushing the water supply lines does not relieve the low water pressure then you can try cleaning them to get rid of any mineral deposits.

Again, close the water supply valves by turning them clockwise then release the remaining water by turning both faucets on.

Grab your wrench and remove both water supply lines underneath the faucet and from the water supply valves too. 

Vinegar can help clean a lot of things and you can use a 50:50 solution with water in a bucket to clean the water supply lines.

Try to pour some of the solution through the lines to clean the interior then leave both of the water supply lines in the bucket overnight and rinse them clean of any remaining vinegar. 

Attach both water supply lines back to their respective places on the water supply valves and underneath the faucet.

Now you can test the water pressure by turning the water back on by the faucets. 

Replace The Water Supply Lines

Just like other appliances in your bathroom, you can replace them with brand-new ones.

This is another last resort if the water supply lines cannot be cleaned sufficiently and the buildup cannot be removed. 

Thankfully, you have already worked out how to remove and put back the water supply lines so it should not prove too difficult to do it again.

Finding the right size of water supply lines can also be straightforward as they can be found in plumbing stores. 

The Flow Restrictor

Just a small white plastic disc could be plugging your faucet as it contains small holes to allow the water through.

In most cases, the flow restrictor works perfectly well to restrict the flow of water when released from the faucet. 

This small white plastic disc is put just inside the aerator mesh inside your faucet and it can be the cause of the low water pressure.

It could be down to the small holes in the flow restrictor being blocked or that the holes are too small which should be simple to fix.

Remove The Flow Restrictor

The first solution is the most drastic which is simply to remove the flow restrictor.

For this potential solution, you will have to unscrew the aerator piece at the end of the faucet and you can use a small wrench or do it by hand if you can. 

Once you have located the flow restrictor, take it out and reattach the aerator mesh to the faucet.

This should allow the water to flow freely yet you will be wasting a flow restrictor that has served you well all this time and you may have to deal with an inconsistent flow. 

Clean The Flow Restrictor

If you want to keep your flow restrictor then you could look to clean it to unclog any blockages.

Start by removing the aerator piece which is at the end of the faucet then scrub it gently with a stiff-bristle brush to get rid of any visible grime and dirt. 

Typically, it is a mineral buildup that results in a clogged hole and if scrubbing does not resolve the problem you can leave the restrictor in white vinegar overnight which should dissolve those minerals to unclog the restrictor hole.

Rinse the restrictor after you can see that the minerals have vanished and put it back in the aerator mesh inside the faucet then test for the water pressure.

Create A Bigger Hole

Remove the flow restrictor after unscrewing the aerator piece and use a screwdriver head or sharp knife to forcibly increase the hole’s size.

This may be quite fiddly as you have to turn some of the plastic and be careful if you are using either method. 

Put the flow restrictor back into the aerator and once the faucet has been attached you can test to see if the water pressure has improved.

If the same problem still occurs then there are several more steps you can take.  

Poor Installation/Servicing

Poor Installation/Servicing

The low water pressure may be a result of poor installation or servicing.

This can be easily checked, easily resolved, and should not take too much time at all. The area you should check is under the sink for the water shutoff valves.

The Water Shutoff Valves 

The water shutoff valves are found underneath the sink and if they are not completely open then that could be the cause.

This could be down to a failure to open them properly after they were initially installed, serviced, or after a winter shut down.

It could even be caused by a bottle of toothpaste or shampoo that has knocked into the valve taps and accidentally closed the valve. 

You may need to place a blanket on the bathroom floor to reach the valves and check that they are fully open.

At the same time, you can also clean up underneath the sink using some typical household cleaning products.

Check both the hot and cold water valves are fully opened as far as they can be.

Water Leaks/Broken Parts

Occasionally, the passage of time can dictate that parts in your appliances and water system can deteriorate and then become issues in themselves.

This can include water leaks from your pipes and a broken faucet that can both result in low water pressure. 

Water Leaks

Just a single hole or crack can result in a leaking pipe so if you do find pools of water when you check the water system this is a likely cause.

This would mean that the water pressure reduces before it has even reached the bathroom faucet.

If you cannot find a leak yourself or do not want to check the entire water system then contact a local, qualified plumber for an expert opinion.

Broken Faucet

Even if the pipes are fully intact, a single hole in a bathroom faucet can cause a leak and prevent sufficient water pressure.

Due to using your bathroom faucet several times a day, they can deteriorate over time and become broken simply by being too old. 

You could try to repair certain parts in your faucet, as you can any appliance, yet this can be fiddly and it would make far more sense simply to replace the faucet.

You will need to replace both faucets for them to match up, unless you can simply buy one and not the set of two.  

The Eight Steps To Solving Low Water Pressure In Your Bathroom Sink

Your first step to solving the low water pressure in your bathroom sink is to isolate the problem to ensure it is just the bathroom sink.

Check the showerhead and any other faucets, such as the one in your bathtub, to see if they are working as you would expect them to.

If the water is flowing freely in those but not the faucets in your bathroom sink then checking then adjusting the pressure regulator will likely not change a thing.

The typical problems can be straightforward enough and include the wrong type of shutoff valve fitted underneath the vanity; that same valve can be either defective or partially closed.

Then there is the faucet aerator which can also be partially closed or blocked, finally, the pipe that feeds that specific faucet can be blocked or clogged. 

Once you have identified that your bathroom sink is suffering from low water pressure, there are some simple steps to resolve the problem.

If you have a standard toolkit and a few towels, with a spare afternoon you can get the job done.

This is a systematic approach that should identify the problem so testing while checking is the best policy to save you some time.

Of course, if you cannot solve the problem yourself then you can just call a plumber.

Fully Open The Shutoff Valve

You may want to place a blanket on the bathroom floor for some added comfort while you find the shutoff valves that feed the water to the faucet of your bathroom sink.

There should be two shutoff valves and these are typically found against the wall and below the bathroom sink, they could also be found inside the vanity cabinet to be hidden out of sight.

If both faucets in your bathroom sink are suffering from low water pressure, you will have to check both shutoff valves.

Do each valve individually and grab the handle then turn it counterclockwise until it has reached the fully open position.

This may have solved the problem already so check the water pressure at both faucets and judge how the water pressure has changed.

If it has solved the problem then great, but if not there are several other steps to try. 

Remove The Faucet Aerator

Remove The Faucet Aerator

This is where your rags and towels will also come in handy as you will need to wrap one around the faucet aerator to look after its finish.

With a pair of tongue and groove pliers, grip the faucet aerator through the rag or towel and twist it counterclockwise until it is unscrewed.

Once the aerator is removed, test the water pressure and if there is a lot of it, you can proceed to clean the faucet aerator as the blockage looks to have caused the low water pressure.  

Clean The Aerator

You can use a homemade solution to clean the aerator which is easy to prepare.

Use a large enough bowl and soak the aerator and all its parts in white vinegar for half an hour to dissolve any hard water deposits.

After that time, use a stiff-bristle brush and scrub the components well then rinse fully and you should see the difference. 

Put the aerator back together then screw it back on using the tongue and groove pliers and try the faucet.

Again, if the problem of low water pressure persists then there are even more steps to try.

Turn Off The Water Supply

Make sure that the water supply is off, otherwise, you will have a huge cleanup mission to look forward to in your bathroom.

Locate the main household water shutoff valve which is typically found on the downstream side, close to the water meter on the main pipe which supplies all the water to your home. 

Grab the handle and turn it to the ‘off’ position which should be simple enough.

Now the water supply is turned off, you can proceed to check the valve types properly and remove them.

Remove The Sink Shutoff Valve

If there is any remaining water in the plumbing connected to your bathroom sink, open a faucet to relieve it and catch it in a bucket.

With an adjustable wrench, undo the flexible hose which is connected to the sink shutoff valve.

You can remove the valve with the same wrench by unscrewing the compression fitting which connects the shutoff valve to the feed pipe.

Check The Valve Types

Two valve types are typically found in a bathroom sink system.

Check inside the outlet pipe on the sink shutoff valve that you have just removed and slowly turn the handle until it is fully in the closed position. 

Should you have to screw the handle down a few times to close the valve, it looks like you have a compression valve that may be faulty.

However, if you spot a round copper ball located below the handle rotating when you look inside the opening then you have a ball valve. 

Replace The Shutoff Valves

It is a good idea to replace the sink shutoff valves simply for servicing or maintenance and you can pick up new valves as replacements from your nearest plumbing store.

When replacing the valves, use an adjustable wrench to attach the compression fitting on the supply lines that leads to the valves.

You can test the faucet after you have reconnected the flexible pipes that lead to the faucets and opened up the household water shutoff valve. 

Call A Qualified Plumber

Call A Qualified Plumber

At this point, if the water pressure is still low, feel free to contact a local, qualified plumber as you have exhausted most possibilities.

You should ask the plumber to focus on any leaks in the pipe that feeds water to your bathroom sink and then test the water flow through that pipe. 

Should there be no leaks and your home uses galvanized piping then it is likely that the feed pipe is clogged with water deposits and rust.

This is another factor that your plumber should advise you on as the feed pipe should be replaced.

Final Thoughts

Once your water pressure begins to drop in a bathroom sink it can become very frustrating.

It is a problem that will not relieve itself but can be resolved easily with a few household tools and a couple of towels or rags.

If you can isolate the problem to the bathroom sink then you can simply focus on that.

Remove and clean certain parts such as the water aerator, flow restrictor, and water supply lines. 

If you have checked the water pipes and the faucet itself and still cannot work out the problem then your best resolution is to contact a local, qualified plumber.

They will be able to inspect the entire water system and work out what the problem is.

It may be the case of replacing a few parts and your water pressure should be back up to normal in no time at all. 

Frequently Asked Questions

What Are The Most Common Causes Of Low Water Pressure In The Sinks In A Home?

In a bathroom sink, the most common causes of low water pressure are clogged parts, water leaks, and the faucet being broken.

A kitchen faucet can be a little different as it is more likely to suffer from clogged pipes due to it being more likely that debris such as solidified oil and grease as well as food particles and foreign objects can get lodged. 

If the pipes are clogged then this can be backed up and cause fractures in the water main.

The issue of mineral buildup can also occur in these pipes which will also cause the water pressure to drop. 

How Do I Increase The Water Pressure In My Pipes?

It is possible to increase the water pressure in your pipes and you do need to locate the main supply pipe to your home which can be simply done.

This should be near the water meter and once you find the conical valve with a bolt sticking out of the cone you can turn it clockwise to increase the water pressure. 

You may need a wrench to turn the bolt clockwise, and to loosen the locknut which is typically very tight.

Check the gauge to ensure that the water pressure remains within the correct bounds, then you can tighten the locknut again using the wrench.

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By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age