A common problem in a kitchen faucet is low water pressure. Low water pressure in a kitchen faucet can be caused by clogs, corrosion in the pipes, or delivery pressure from the main source. Identifying the problem will help greatly in the actual repair, making it fairly easy if the troubleshooting is done properly. However, there may still be times when you will need to call in a professional.
Step 1 - Identify the Problem
Problems with water pressure can be divided into two main categories, based on whether or not the problem is persistent throughout your home.
Pressure Problems in Entire House
If you have remodeled your home to increase living space and added more water fixtures, you may have decreased your water pressure. You will need to put in a larger water main pipe to fix this problem.
If you have low water pressure throughout your home, a supplemental booster pump in the line should keep the water pressure up. Both of these types of fixes are best conducted by a plumbing professional.
Kitchen Faucet Only
If you find that the low pressure is only in the kitchen faucet, the cause is likely debris in one of several places leading up to the faucet. These problems fortunately can be fixed by DIYers. Start looking for the cause by first checking the aerator screen on the faucet, following the rest of these steps after to free your fixtures and piping of clogs or debris.
Step 2 - Unscrew the Aerator Screen
On most faucets there is a small screen at the end of the faucet spout where the water comes out. Unscrew the spout by hand and remove any blockage in the screen. You may find sediment clogging the screen as well, but removing sediment is a minor cleaning project.
Unscrew the aerator. Disassemble it and soak the parts in a warm water and vinegar solution. If the blockage remains, you can try a commercial calcium remover. Dry the spout, reassemble, and reattach to the faucet.
Once it is replaced, turn on the faucet to see if pressure has been restored.
Step 3 - Remove the Faucet Head
In some faucets the cartridge that moves to allow the water to pass through can malfunction or stick. You can easily replace it or free it from items keeping it closed. To remove the faucet head, find the screw under the faucet spout. Unscrew it and lift off the faucet head. The cartridge should be open. If not, remove the thin housing. Clean everything of debris or calcium buildup with calcium remover. Replace the thin housing and faucet head.
Try the faucet again to see if the water is flowing as it should.
Step 4 – Solve an In Line Problem
You may have a buildup in the pipe leading to the faucet. If the piping is galvanized piping, it's most likely accumulated debris from age and sediment. You can remove or unscrew the riser from the basement with a pipe wrench. Back up the fitting in the basement so the fitting or pipe attached does not break. With a bucket and another person, turn the water on and see what the pressure is from the pipe that you just removed. If it’s good, replace the piece that you just removed. If it’s not good, a re-pipe of the entire home will be needed.
TIP: If you are in a crawl space you can do the same thing, but you might need a second person to unscrew the riser from under the kitchen sink. Of course both of these are only necessary if the piping is coming up through the floor of the cabinet. If the pipes are coming out of the wall, the wall needs to be opened to remove the 90 degree elbow before removing the riser.