Kitchen Sink Water Pressure Low? Check This First
Is your kitchen faucet barely dripping out water? Do you have to wait forever to fill a glass or pot? Low water pressure in your kitchen sink can quickly go from annoying to making your sink virtually unusable.
But before you call a plumber, there are several easy things you can check yourself to get your kitchen faucet flowing again.
What Causes Low Water Pressure in a Kitchen Sink?
There are a few common culprits behind decreasing water pressure from your kitchen tap:
- Clogged aerator
- Blocked or faulty sink cartridge
- Partially closed supply valve
- Leak in the supply line
- Clogged supply line
Issues like mineral buildup and debris can clog components like aerators and cartridges. Old galvanized pipes may have corrosion that blocks flow. Leaks and closed valves also restrict how much water can come out of your faucet.
The good news is that many of these common causes of low kitchen sink water pressure can be fixed yourself without calling a plumber.
How to Check For Issues
Diagnosing the cause of low water pressure requires a bit of kitchen sink troubleshooting. Here are a few things to check before doing any repairs:
Check Under the Sink
The first step is to look under your kitchen sink. Turn on the faucet and inspect the supply lines, drain pipes, shutoff valves, and connections. Look for:
- Dripping water indicating a leak
- Corrosion on metal pipes
- Cracks or kinks in the supply lines
- Loose fittings
Tighten any loose joints. Replace old corroded galvanized pipes. Look for wet areas that may indicate a leak. Leaks and corrosion both can decrease water volume.
Remove and Inspect the Aerator
The aerator is a small screen on the tip of your faucet spout. Unscrew this piece and examine it. You may find:
- Mineral deposits and debris clogging the screen
- Corrosion
- Damage to the aerator threads
Soaking the aerator in vinegar can help dissolve any stubborn deposits. A damaged aerator should be replaced.
Check the Water Pressure
Use a water pressure gauge to check the PSI (pounds per square inch) from your kitchen faucet. Turn on the tap and compare the pressure to other faucets in your home. If your kitchen sink pressure is noticeably lower, that points to an issue with that faucet rather than your home's main water pressure.
Inspect Shutoff Valves
Make sure the shutoff valves under your kitchen sink are fully open. These gate valves can get bumped and partially closed by accident. Ensure each valve is turned as far counterclockwise as it will go for maximum water flow.
How to Fix a Clogged Aerator
A clogged aerator is one of the easiest fixes for low kitchen faucet pressure. Aerators have small screens that easily get blocked by mineral deposits, sand, and debris.
To clean a clogged aerator:
- Unscrew the aerator from the tip of the faucet spout (this usually just needs to be turned counterclockwise by hand).
- Use a toothbrush and vinegar to scrub off any stuck-on deposits.
- Rinse thoroughly with water.
- Make sure the screen hasn't become deformed. If needed, straighten it out carefully with pliers.
- Replace the washed aerator on your faucet.
Be careful not to lose any small washers or o-rings that are part of your faucet's aerator assembly. With the debris washed away, new water flow should be restored.
Fixing a Faulty Sink Cartridge
The cartridge is the part inside your faucet that controls water flow and mixing. Over time, cartridges can get clogged with mineral deposits and wear out.
Signs your kitchen faucet cartridge needs to be cleaned or replaced:
- Water flow is weaker than normal
- Water temperature fluctuates
- Faucet leaks from around the base
- Water drips after the faucet is turned off
Removing the Cartridge
Start by shutting off the water supply valves below your sink. Open the faucet to relieve any built up pressure. Follow the manufacturer's instructions for removing your specific faucet cartridge.
In most cases, you'll need to remove the faucet handle first by unscrewing the handle screw. Then find and take out the cartridge retaining clip. At this point you can pull the cartridge straight up and out of the faucet body.
Cleaning and Replacing Cartridges
Rinse the cartridge with water and scrub it with an old toothbrush to remove any debris. Compressed air can also be used to clear out the inlet ports.
Inspect closely for any cracks or damage. Worn out or broken cartridges will need to be replaced. Take the old cartridge with you to find an exact match at the hardware store.
Re-install the cleaned or new cartridge by following the removal steps in reverse. Make sure it is fully inserted and the retaining clips are snapped into place. Turn the water back on slowly and check for leaks.
Checking for Supply Line Leaks
If cleaning the aerator and cartridge haven't helped, its time to thoroughly inspect your sink's supply lines.
Inspect Shutoff Valves
Examine the compression fittings on the shutoff valves connected to your supply pipes. Tighten any loose nuts and replace any valves with cracks or corrosion.
Check under Appliances
Appliances like dishwashers also have supply lines that branch off from the kitchen sink. Inspect under and behind appliances for any water on the floor that may indicate a leak.
Look For Drips at Night
Some leaks only occur when water is flowing. Check your connections in the evening when the kitchen sink tap has been running to spot hard-to-find drips.
Test with Air Pressure
An air pressure tester can be used to pressurize supply lines and detect even tiny leaks. This tool is available at most hardware stores.
Fixing a Leaky Pipe Joint
If you find a leaking pipe joint under your sink, the first step is to turn off the shutoff valve for that supply line. Place a container under the leak to catch any remaining water.
Take apart the joint and inspect for cracked washers. Replace old washers with exact duplicates. Apply plumber's tape to wrapped connections before re-tightening.
For compression fittings, tighten the nut further or unscrew it to reset the pipe in place. Some leaks may require replacing entire sections of old steel pipes.
Is Your Main Water Line Leaking?
If every faucet in your home has low pressure, the issue is likely with your main supply line, not your kitchen sink. Inspect the main line valve for leaks. Check your water meter when no water is running - movement indicates a leak.
Major underground pipe leaks will require professional repair. Make sure to call in an emergency plumber if you have very low water pressure throughout your home.
Installing Water Pressure Booster Pumps
If your home's overall water pressure is simply inadequate, installing a booster pump can help. This brings your household water pressure up to a normal PSI level.
Look for a pump that can provide at least 50 to 60 PSI. Most units install under the sink but there are also small inline models.
Just keep in mind that unless you address issues like leaks, a new pump won't fix low water pressure on its own.
When to Call a Professional Plumber
While many water pressure fixes are DIY, some issues do require a professional:
- Main supply line leaks
- Re-piping corroded steel pipes
- Major repairs under flooring or behind walls
- Persistent leaks of unknown origin
If you've addressed common problems like the aerator, cartridge, and valves but water pressure is still low, its best to call a pro. Leaving leaks unaddressed can cause water damage or mold.
Preventing Low Water Pressure Problems
To help avoid low kitchen sink water pressure in the future:
- Clean aerators and showerheads every few months
- Replace old galvanized steel pipes
- Choose metal braided supply lines
- Update worn out shutoff valves
- Fix any leaks quickly
Investing in some preventative maintenance can help keep your kitchen faucet pressure where it needs to be.
Don't live with a faucet that barely trickles. In many cases, low kitchen sink water pressure can be addressed with some easy DIY troubleshooting and repairs.
Start by checking for clogged aerators, worn out cartridges, and leaks around shutoff valves. Fixing these common problems yourself can restore normal water flow and pressure.
But for major leaks or re-piping, rely on a professional plumber. Restoring adequate water pressure prevents damage and makes sure your kitchen sink works properly.