Kitchen sink plumbing and replacement in San Jose
Under-sink leaks, new sinks and extra taps all come down to the same few connections done properly.
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Perfect Tankless Plumbing, San Jose, CA
Kitchen sink plumbing in San Jose covers the P-trap and drain assembly, sink replacement, supply stops and lines, and add-ons like pot fillers and instant hot water taps; older homes often need the stop valves and the drain arm into the wall replaced at the same time.
Updated September 2026
Fixtures & Bath
What sits under a kitchen sink
Under a kitchen sink there is a lot packed into a small cabinet: two supply stops, the faucet lines, a trap, the drain arm into the wall, often a disposal and a dishwasher drain. Most leaks start at slip-joint nuts, worn washers or a corroded drain arm.
When a sink is replaced or a new tap is added, we check each of those connections rather than joining new parts to old ones that are about to fail.
Cost factors
What changes the cost of kitchen sink work
We do not publish a local price for sink work; what is connected under it sets the scope.
- What is being replaced. a trap, a faucet, or the whole sink
- Undermount or drop-in. undermount sets take longer
- Old stops and drain arm. replaced when corroded
- Disposal and dishwasher. reconnection or replacement
- New supply runs. pot fillers and fridge lines
- Countertop work. cutting and sealing is usually by others
Options
Undermount or drop-in sink
| Undermount | Drop-in | |
|---|---|---|
| Counter type | Stone or solid surface | Any, including laminate |
| Cleaning | Wipe straight into the bowl | Rim can collect grime |
| Installation | Clips or brackets under the counter | Rests on the cutout |
| Replacement later | More involved | Simpler |
| Look | Clean edge | Visible rim |
| Plumbing | Same connections | Same connections |
DIY or call
Sink jobs you can do and the ones to hand over
| Task | Reasonable to DIY | Call a plumber |
|---|---|---|
| Tightening a slip nut | Yes | If it keeps leaking |
| Clearing the trap | Yes, with a bucket | If the clog is past the wall |
| Replacing supply lines | Yes, with working stops | If the stops leak |
| Replacing a stop valve | No | Old galvanized threads |
| Replacing the drain arm | No | Always |
| Adding a pot filler | No | Always |
P-trap and drain assembly
Kitchen drain assemblies loosen with the vibration of a disposal and the weight of a full sink. We replace worn slip-joint washers and nuts, or the whole assembly when it is old chrome-plated brass or thin plastic, and set the trap at the right height so it drains the disposal and the second bowl properly. If the drain arm into the wall is corroded galvanized, we replace it back to sound pipe so the new trap has something solid to connect to.
Sink replacement
Replacing a kitchen sink means disconnecting the faucet, disposal, dishwasher drain and trap, removing the old sink, and setting the new one level and sealed. Undermount sinks are supported with clips or brackets rated for the weight; drop-in sinks are sealed at the rim. We reconnect everything with new supply lines and check the trap height for the new bowl depth. Deep single bowls often need the trap and drain arm lowered to drain properly, which is simple before the new sink is set and awkward afterwards.
Pot filler and instant hot
A pot filler needs a cold supply run to the wall behind the range, with a shutoff somewhere accessible. We route it through the wall or cabinet, set the valve and mount at a comfortable height, and pressure test before the wall is closed. Instant hot water dispensers need a supply tee, a small tank under the sink and an outlet. We plan both so they do not crowd the cabinet, block the disposal or leave the shutoffs out of reach when something needs servicing later.
Local context
Old stops and drain arms in pre-1970 San Jose kitchens
More than 40 percent of San Jose housing was built before 1970, and in those kitchens the supply stops and threaded connections are often original. A faucet swap that should take an hour can turn into a short branch repair when an old nipple crumbles as the valve is removed. We carry stops, nipples and drain arm fittings on kitchen calls so that repair can be finished in the same visit rather than waiting for parts.
How the job runs
How kitchen sink work runs
- 1
Check what is there
Stops, trap, drain arm and connections.
- 2
Shut off and disconnect
Supplies, disposal and dishwasher drain.
- 3
Replace what is failing
Stops, drain arm or assembly.
- 4
Set the sink or fixture
Level, sealed and supported.
- 5
Reconnect
New lines, trap at the right height.
- 6
Test
Fill both bowls, run the disposal, check for drips.
FAQ
Kitchen Sink Plumbing questions from San Jose homeowners
Usually loose slip nuts or worn washers, sometimes a corroded drain arm. We replace what has failed.
Yes. We check it fits the cabinet and counter cutout before starting.
Stone cutting is usually done by the fabricator. We handle the plumbing and sink setting.
Yes, by running a cold supply through the wall or cabinets behind the range.
If they are old or won't close fully, yes, while the water is already off.
Same family
Related work in fixtures & bath
Sump Pump Installation
Crawl space pump, Battery backup.
Sump Pump Installation in San JoseGarbage Disposal Installation
Jammed or humming disposal, New disposal install.
How we handle garbage disposal installationFaucet Repair and Replacement
Cartridge replacement, Kitchen faucet swap.
Faucet Repair and Replacement in San JoseBathtub Installation and Repair
Tub drain and overflow, Tub to shower conversion.
Read about bathtub installation and repairShower Repair
Shower valve replacement, Cartridge and diverter.
How we handle shower repair
One number, any hour
Book your kitchen sink work
Call and tell us what is leaking or what you are adding. We will bring the parts.
