A dripping bathroom faucet at one drop per second wastes roughly 3,000 gallons of water per year — and that's a slow drip. St. Louis municipal water at 60–80 PSI through a failing cartridge or worn seat washer produces steady loss. STL Plumbing Pros repairs all bathroom faucet types — cartridge, ball, ceramic disc, and compression — across St. Louis City, County, and surrounding areas. Most repairs are completed same-day with parts on the truck.
What Causes Bathroom Faucet Problems?
Worn cartridge (cartridge faucets)
The most common bathroom faucet type in St. Louis homes built after 1980. The cartridge controls both volume and temperature. Over time the cartridge O-rings and sealing surfaces wear and the faucet drips. Cartridge replacement is a straightforward repair — 30–45 minutes for most configurations.
Worn ceramic disc (disc faucets)
Higher-end faucets use two ceramic discs that rotate against each other. Ceramic discs are extremely durable but can crack from thermal shock or mineral deposit pressure. A cracked disc causes leaking that cannot be fixed by tightening — the disc requires replacement.
Worn seat washer (compression faucets)
Found in older St. Louis homes — two-handle faucets where you tighten a handle to stop flow. The rubber seat washer compresses against a brass seat. As the washer wears, more handle pressure is needed to stop the drip. Washer and O-ring replacement typically resolves it.
Warning Signs Your Bathroom Faucet Needs Repair
Dripping from the spout when the handle is fully closed
Water around the base of the faucet body — handle seal or O-ring failure
Reduced flow from one or both handles — aerator mineral blockage or cartridge scale
Handle is stiff or difficult to operate — cartridge or disc binding
Hot and cold reversed or mixed incorrectly — cartridge installed incorrectly or worn
Leaking from under the sink — supply line connection or shutoff valve
How We Diagnose and Repair Bathroom Faucets
Identify Faucet Type and Failure Mode
Cartridge, compression, ball, or ceramic disc — each requires a different part and procedure. We identify the brand and model, determine the failure point (spout drip, base leak, or low pressure), and test all three before quoting.
Cartridge or Component Replacement
Shut off supply, disassemble handle and bonnet nut, remove worn cartridge or seat washer, install new component with new O-rings, reassemble. For mineral-damaged aerators: soak in vinegar, rinse, or replace.
Full Flow and Leak Test
Restore supply, run both hot and cold at full pressure, confirm drip-free shutoff, check base and under-sink for secondary leaks. Handle operation should be smooth through the full range.
What Does Bathroom Faucet Repair Cost?
| Service | Price | Details |
|---|---|---|
| Cartridge replacement (single or double handle) | $125–$225 | Parts plus labor. Cost varies by brand. |
| Seat washer replacement (compression faucet) | $100–$175 | Common in older two-handle bathroom faucets. |
| Ceramic disc replacement | $150–$275 | Disc sourcing depends on faucet brand and age. |
| Aerator cleaning or replacement | $75–$125 | Often combined with a cartridge repair visit. |
| Supply line replacement | $85–$150 | Braided stainless supply line from shutoff to faucet. |
| O-ring and base seal repair | $100–$175 | For leaks around the faucet body base. |
Repair vs. Replace — When Each Makes Sense
Repair is almost always the right answer for a faucet that is structurally sound and under 15 years old — cartridges, washers, and O-rings are inexpensive. Replace when:
The faucet body is cracked or corroded to the point where a cartridge replacement won't hold.
The brass valve seat is pitted or corroded and cannot be re-faced.
The faucet brand is discontinued and replacement cartridges are unavailable or prohibitively expensive.
The homeowner wants to upgrade fixture style alongside the repair visit.
Why Choose STL Plumbing Pros?
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All Faucet Types, Parts on the Truck
We carry cartridges for Moen, Delta, Kohler, American Standard and common O-ring and washer assortments. Most repairs don't require a parts run.
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We Address the Mineral Scale Issue
St. Louis water produces scale in aerators and cartridges faster than in soft-water markets. We clean or replace the aerator on every faucet repair visit.
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Diagnose First, Quote After
We identify the specific failure before quoting. A dripping faucet is not always a cartridge — it might be a $75 aerator fix or a $150 supply line.
What Our Customers Say
"Dripping bathroom faucet that had been annoying us for months. Plumber identified the cartridge, replaced it in 30 minutes, and cleaned the aerator too. Full pressure restored, no more drip."
"Low pressure in the master bath faucet. Turned out to be mineral buildup in the aerator — plumber soaked and cleaned it while also replacing a worn O-ring on the base. Two problems fixed in one visit."
"Old two-handle bathroom faucet where you had to really crank the hot handle to stop the drip. Plumber replaced the seat washers and O-rings. No more drip, handles operate smoothly. Should have called sooner."