Only one faucet has low pressure
Other sinks, showers, or tubs seem normal, but one faucet is weak on both hot and cold.
Start here: Start with the faucet aerator, then check both shutoff valves under that sink.
Faucet pressure problem
Faucet Low Pressure
Direct answer: Low faucet pressure is most often caused by a clogged faucet aerator, a partly closed shutoff valve, debris in the faucet cartridge, or a kinked faucet supply hose. First figure out whether the problem affects one faucet, one side only, or the whole house.
Most likely: If only one faucet is weak and the flow used to be normal, start with the faucet aerator and then compare hot versus cold flow to narrow the branch.
Low pressure can look similar whether the restriction is at the faucet tip, inside the faucet body, or farther back at the shutoff or supply line. A quick pattern check saves time: one faucet versus several fixtures, hot only versus cold only, steady weak flow versus a sudden drop. Start with the easy visible checks before loosening any plumbing connections.
Don’t start with: Do not buy a new faucet or cartridge first. Many low-pressure calls turn out to be a dirty aerator or a valve under the sink that is not fully open.
Only one faucet is weak?Clean the faucet aerator before assuming an internal faucet failure.
Hot or cold only is weak?Compare both sides first, because that usually points to a local valve, supply, or cartridge branch.
Last reviewed: 2026-03-18
What kind of low faucet pressure are you seeing?
Only hot or only cold is weak
One handle position or one side flows much less than the other.
Start here: Compare the weak side to the strong side, then inspect that side's shutoff valve and supply path before suspecting the faucet cartridge.
Pressure dropped suddenly after recent work
The faucet was normal before a shutoff, repair, or water service interruption.
Start here: Debris may have broken loose into the aerator or faucet cartridge, so begin with the aerator and flush the lines carefully.
Several fixtures have low pressure
More than one faucet or fixture is weak, or the whole house seems affected.
Start here: This page can help rule out a local faucet issue, but if multiple fixtures are weak, check the main supply situation before taking the faucet apart.
Most likely causes
1. Clogged faucet aerator
Mineral buildup and small debris collect at the faucet tip and can reduce flow on both hot and cold, sometimes suddenly after plumbing work.
Quick check: Unscrew the faucet aerator, inspect the screen, and briefly run water into a bucket or the sink without the aerator.
2. Partly closed faucet shutoff valve
A stop valve under the sink that is not fully open can choke flow to one side or both sides, especially after cleaning, storage, or recent repairs.
Quick check: Look under the sink and confirm the hot and cold shutoff valves are turned fully open and not obviously damaged.
3. Kinked or restricted faucet supply hose
A bent braided line or pull-down hose can reduce flow, often on one side only or when the faucet was recently moved.
Quick check: Inspect the faucet supply hoses and, on pull-down faucets, the sprayer hose path for sharp bends, twists, or something pressing against them.
4. Debris in the faucet cartridge
If the aerator is clear but the faucet still has weak flow, sediment inside the faucet cartridge can restrict water through the mixing path.
Quick check: After cleaning the aerator and confirming valves are open, note whether the faucet still stays weak on one or both sides with a steady restricted stream.
Step-by-step fix
Step 1: Separate a local faucet problem from a supply problem
You do not want to take apart a faucet if the real issue affects multiple fixtures or started with a broader water supply change.
- Turn on at least one other faucet in the home and compare the flow.
- At the problem faucet, compare hot and cold flow separately.
- Note whether the weak flow is only at one faucet, only on one temperature side, or throughout the house.
- If the problem started right after utility work, a shutoff, or plumbing repairs, keep debris in mind as a likely branch.
Next move: If you confirm the problem is limited to one faucet, continue with local faucet checks. If several fixtures are weak, the issue is probably not inside this faucet alone.
What to conclude: One-faucet low pressure usually points to the aerator, local shutoff valves, supply hoses, or the faucet cartridge. Whole-house low pressure points elsewhere.
Stop if:
- Multiple fixtures suddenly have very low flow and you are not sure where the restriction is.
- You hear banging, see leaks, or notice discolored water that does not clear quickly.
- A main shutoff or pressure-related issue seems more likely than a faucet issue.
Step 2: Remove and clean the faucet aerator
This is the most common and least destructive fix for low faucet pressure, especially when the drop was sudden or affects both hot and cold.
- Close the sink drain so small parts cannot fall in.
- Wrap the faucet aerator with a soft cloth if you need extra grip, then unscrew it by hand or with pliers used gently over the cloth.
- Rinse out loose grit and inspect the screen for mineral buildup.
- Soak the aerator in warm water and mild soap first. If mineral scale remains and the finish is not delicate, a short soak in plain vinegar can help loosen deposits.
- Rinse thoroughly, reassemble the aerator, and reinstall it.
- If the aerator was heavily clogged, briefly run the faucet without the aerator first to flush loose debris into the sink.
Next move: If flow returns to normal, the restriction was at the faucet outlet and no parts are needed right now. If flow is still weak with the aerator off or returns weak again immediately, move to the shutoff and supply checks.
What to conclude: A clogged aerator is a simple local restriction. If removing it does not improve flow, the restriction is farther upstream in the faucet or supply path.
Step 3: Check the faucet shutoff valves under the sink
A partly closed or failing shutoff valve can mimic a faucet problem and often affects only hot or only cold.
- Place a towel under the valves and look for any active drips before touching them.
- Turn each faucet shutoff valve gently clockwise until it stops, then reopen it fully counterclockwise unless it is a quarter-turn style, which should align with the open position.
- If one side was partly closed, test the faucet again.
- If a valve handle spins freely, binds hard, or starts leaking around the stem, stop using force.
Next move: If pressure improves after fully opening a valve, the restriction was at that local shutoff. If both valves are fully open and the faucet is still weak, inspect the supply hoses and faucet path next.
Step 4: Inspect the faucet supply hoses and sprayer hose path
Kinks, twists, or internal hose restrictions can reduce flow even when the aerator and shutoff valves are fine.
- Look at the hot and cold faucet supply hoses under the sink for sharp bends, crushing, or something stored against them.
- If you have a pull-down or pull-out faucet, check that the sprayer hose hangs freely and is not snagged on cleaning supplies, the drain, or the cabinet wall.
- Straighten any obvious kink carefully without over-bending the hose.
- Run the faucet again and compare the flow.
Repair guide: How to Replace a Faucet Supply Hose
Related repair guide: How to Replace a Faucet Sprayer Hose
Step 5: Suspect the faucet cartridge only after the simple checks fail
Once the aerator, shutoff valves, and hose path are ruled out, debris or wear inside the faucet cartridge becomes a stronger diagnosis.
- Note whether the low flow is on one side only or through the full handle range.
- If the problem began after plumbing work, sediment may be trapped inside the faucet cartridge.
- Shut off the faucet supply valves before any disassembly.
- If you are comfortable with faucet disassembly, remove the handle and inspect the faucet cartridge area for debris or obvious damage, following the faucet's normal service method.
- If the cartridge is visibly damaged, hard to move, or cleaning does not restore flow, replace it with a matching faucet cartridge.
Repair guide: How to Replace a Faucet Cartridge
A good result: If cleaning or replacing the faucet cartridge restores normal flow, the internal faucet restriction was the cause.
If not: If a new matching cartridge does not fix the problem, the issue may be in the local shutoff valve, supply line, or a broader plumbing restriction that needs a plumber.
What to conclude: A faucet cartridge branch is supported when the outlet is clear, valves are open, hoses are not kinked, and the faucet still has restricted flow.
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FAQ
Why does only one faucet have low pressure?
When only one faucet is weak, the cause is usually local to that faucet: a clogged faucet aerator, a partly closed shutoff valve, a kinked faucet supply hose, or debris in the faucet cartridge.
Why is my faucet low pressure on hot water only?
Hot-only low pressure often points to the hot shutoff valve under the sink, a restriction in the hot faucet supply hose, or debris affecting the faucet cartridge's hot side. Compare hot and cold first before taking the faucet apart.
Can a clogged aerator really make the faucet pressure drop that much?
Yes. A faucet aerator can collect enough mineral scale or debris to reduce flow dramatically, especially after plumbing work or a water interruption. It is the safest first check because it is easy to inspect and clean.
Should I replace the whole faucet if the pressure is low?
Usually no. Whole faucet replacement is rarely the first answer for low pressure. Rule out the faucet aerator, shutoff valves, hose restrictions, and the faucet cartridge first.
What if all the faucets in my house have low pressure?
If several fixtures are weak, the problem is probably not one faucet. Check for a broader supply issue, a partially closed main valve, or a neighborhood water problem before focusing on this faucet.
Can low faucet pressure come back after I clean the aerator?
Yes. If the faucet aerator clogs again quickly, debris may still be in the faucet or supply line. Flush the faucet briefly with the aerator removed, then if the problem continues, look farther upstream at the shutoff valves, hoses, or faucet cartridge.