Low water pressure in the kitchen sink can be an inconvenience.  Low water pressure is a common problem in kitchen sinks, which could be from numerous causes from blockages to water heaters. A common cause of low water pressure comes from mineral deposits breaking of in pipes. Fortunately, you should be able to diagnose the causes yourself by following these instructions:

Check Water Pressure 

You need the following supplies:

• work gloves
• plastic tape
• flat-blade screwdriver
• Allen wrench
• water valve wrench
• slip-joint pliers
• vinegar
• old toothbrush
• towel

The water pressure meter, which is located near your meter, should read between 50 and 60 PSI (Per Square Inch). Use a pressure gauge from a hardware store, or call a plumber to check this for you. In some cases, your pipes may not be large enough to handle the pressure, if you have remodeled. Have larger pipe installed, or add a water booster.

Inspect  Water Valves

The water supply valve near the water meter should be completely open, and the handle must be perpendicular to the pipe. Use a valve wrench to turn the valve to the left.

Do the same for the outlet valves on the hot water heater by rotating it as far to the left as possible. Test other sinks for pressure flow. If the pressure is still low, the pipes could be corroded. 

Clean the Aerator

Insert the stopper in the drain to keep parts from falling into it, then spread a towel over the counter. Detach the sink aerator from the end of the faucet body by hand. If it seems stuck, cover the teeth of the pliers with tape, and try to remove it by turning the pliers left.

Look for the small screen on the end of the aerator where water pours out, and check for sediment and dirt. Remove all parts of the aerator; laying them on the towel in order of disassembly. 

The parts include washer, flow restrictor, mixing, and bushing. Soak the parts in a vinegar and water mixture, scrub them with the toothbrush, let them dry, and reassemble it.

Replace damaged parts and screens that didn't come clean. Go to the next step, if cleaning didn't increase water pressure.

Check the Cartridge

Some faucets use a cartridge assembly to direct water, which may get stuck, because of grime. Shut off the water supply valves from under the sink, or turn off the main water supply. 

Pry the cover off with the screwdriver, and use the Allen wrench to remove the set screws, and lay them on the towel. Loosen the retaining nut with slip-joint pliers, then pull the cartridge from the faucet. Soak the cartridge in vinegar and water, reinstall it, then test the pressure. Replace broken or scratched cartridges. 

Contac a plumbing company for more information and assistance.