Commercial Faucet Dripping: Cartridge and Washer Troubleshooting
A faucet that drips after shutoff usually has a worn cartridge, stem washer, seat, seal, or debris preventing a seal. Identify the faucet type before disassembly.
Last reviewed 2026-09-12 · General facility-maintenance information, not a substitute for site procedures, manufacturer instructions, codes, or qualified professional judgment.
Safety boundary
Likely causes
- Worn cartridge
- Damaged stem washer
- Debris on sealing surface
- Worn o-ring
- Damaged valve seat
Symptom → cause → first move
Worn cartridge
Check: Identify manufacturer and faucet style
First move: Clean debris from sealing surfaces
Damaged stem washer
Check: Shut off hot and cold stops
First move: Replace the exact cartridge or stem kit
Debris on sealing surface
Check: Open faucet to relieve pressure
First move: Reassemble and test both shutoff and handle leakage
Worn o-ring
Check: Remove handle and trim carefully
First move: Clean debris from sealing surfaces
Damaged valve seat
Check: Inspect cartridge, stem, and seals
First move: Replace the exact cartridge or stem kit
What to check first
Bring these
- Flashlight
- Rags or towels
- Basic hand tools appropriate to the fixture
- Correct manufacturer repair parts when needed
Before touching anything
- Confirm the exact location and complaint.
- Photograph labels, settings, fault codes, and the original condition.
- Determine whether the failure affects one item or several nearby items.
- Know how to safely isolate the system if the task requires it.
Step-by-step procedure
- 1Identify manufacturer and faucet stylePhotograph the brand, handle arrangement, and cartridge identification; a similar-looking cartridge is not proof of compatibility.
- 2Shut off hot and cold stopsClose both fixture stops gently and confirm flow stops when the faucet is opened; do not dismantle a faucet with a passing or seized stop.
- 3Open faucet to relieve pressureLeave the faucet open to release trapped pressure, protect the drain against lost parts, and catch residual water.
- 4Remove handle and trim carefullyFollow the model's handle and retaining-clip sequence; place parts in order and do not pry against the ceramic sink.
- 5Inspect cartridge, stem, and sealsCheck the cartridge and sealing seats for damage or grit. Install the specified part, restore water slowly, and verify shutoff and dry joints through several hot/cold cycles.
Routine fixes that make sense here
- Clean debris from sealing surfaces
- Replace the exact cartridge or stem kit
- Reassemble and test both shutoff and handle leakage
Stop and call a licensed professional when
- Supply stops do not hold
- Faucet body is cracked
- Cartridge is seized badly enough to risk breaking the body
Common mistakes
- Replacing parts before proving the failure.
- Changing several settings or components at once.
- Failing to photograph the original condition.
- Ignoring whether nearby equipment has the same symptom.
- Crossing into electrical, refrigerant, life-safety, structural, or plumbing work beyond training.
FAQ
What should I check first?
Start by deciding whether the problem is local to one fixture or piece of equipment. Then begin with the simplest safe observation: identify manufacturer and faucet style.
What is the most common mistake?
Replacing parts before proving the failure. BuildingWrench recommends documenting the symptom, changing one thing at a time, and testing after each change.
When should maintenance stop?
Stop when the repair crosses your training or site-safety boundary. In this case, one clear handoff point is: supply stops do not hold.
What should I document?
Record the exact location, model or asset tag, what the equipment was doing, what you checked, what you changed, and whether the fix held through repeated testing.
Parts for this repair
Gasket and O-ring assortment
Common seals for compatible faucets, valves, and mechanical repairs.
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