How to unclog a kitchen sink: start with the trap
Start under the sink, not at the plughole. HDB's guide to sinks and wash basins says the common trap for kitchen sinks and wash basins in HDB flats is the bottle trap. HDB also says chokes in this trap come from solid matter or hardened grease. In a kitchen, that means food scraps and cooking grease collecting just below the sink outlet.
The trap is the part of the drain you can open yourself, so begin there. If your sink has a different kind of trap, check how it comes apart before you unscrew anything. The steps below are for a bottle trap.
Clear the bottle trap
The steps below follow HDB's method for clearing a bottle trap. This is the standard sink choke DIY job: you need a bucket, a cloth and a wire hook or a thin stick.
- Catch the water. Put a bucket directly under the bottle trap and lay a cloth around it. Water and waste will come out when you open the trap.
- Twist off the lower section. Turn the lower part of the trap anti-clockwise until it comes free.
- Remove the solid matter. Pick out the waste inside with a wire hook or a thin stick.
- Flush it with water. Rinse the lower section until the water runs clean. Do this over the bucket or at another tap, as this sink has no trap fitted yet.
- Screw it back on and test. Fit the lower section back on clockwise until it is snug. Run the tap for a while and check under the trap for drips.
If it still drips after you refit it, the trap may need replacing. If the water still backs up, the choke is further down the pipe.
If the sink is still blocked
If the trap is clear and water still backs up, the choke is beyond the trap, in the discharge pipe. A kitchen sink blocked at that point needs the pipe cleared, which is a job for a plumber or handyman.
PUB's Plumbing Works page lists clearing any blockage in a sanitary appliance, such as a sink, as simple plumbing works. The list also covers clearing and flushing any discharge pipe carrying used water from a sanitary appliance to the sewerage system. A handyman may do simple plumbing works without a PUB licence.
FROM THE HOMEZYPRO DIRECTORY
Published choke clearing rates
For the most common unit (per job), the lowest published choke clearing rates from 22 companies run from S$50 to S$150 per job (middle rate S$80), to clear one choke in a toilet bowl, floor trap or sink. The middle figure is a real published rate, not an average. Each figure is one company's own advertised rate with its conditions, not a quote.
See 22 published choke clearing rates and sources
| Company | Service as listed | Rate | Source |
|---|---|---|---|
| Kiasu Plumber | Remove kitchen sink choke | From S$50 per job | kiasuplumber.com |
| SG1 Plumber Singapore | Floor-trap Choke Cleaning | S$50 per job | sg1plumber.com |
| AquaHero Plumbing | Clear Clogged Floor Trap | S$60 per job | aquahero-plumbing.sg |
| EZ Plumber SG | Clear Clogged Floor Trap | S$60 per job | ezplumber.sg |
| Plumber - Singapore Plumbing 24hrs | Supply Labour to Clear Toilet Bowl Choke | From S$60 per job | singaporeplumbing24hrs.com.sg |
| Sin Plumbing Singapore | Clear clogged floor trap | From S$60 per job | sinplumbing.com |
| Uncle Plumber | Clear clogged floor trap | From S$60 per job | uncleplumber.sg |
| GD Plumbing | Clogged toilet bowl / Clearing toilet bowl choke | From S$70 per job | gdplumbing.com.sg |
| Hdbplumber Service SG | Clearing toilet bowl choke | From S$79 per job | hdbplumberservice.com.sg |
| Ace Plumbing Specialist | Clogged toilet bowl / clearing toilet bowl choke | From S$80 per job | aceplumbing.sg |
| Active Plumbing Singapore | Clearing toilet bowl choke | From S$80 per job | activeplumbing.sg |
| Home Plumbers Singapore | Clear a toilet bowl choke | From S$80 per job | homeplumbers.com.sg |
| PlumbersGuru Singapore | Basic unclogging starts . Complex jobs with grease traps or root intrusion cost more. We | From S$80 to S$150 per job | plumbersguru.com |
| PW Plumbing Services | Toilet Choke Clearing | S$90 to S$150 per job | pwplumbing.com.sg |
| SR Power Plumber Pte. Ltd. | Clearing toilet bowl choke / clogged toilet bowl | From S$90 per job | srpowerplumber.com |
| Huat Plumbing | Toilet Bowl Choke Clearing | From S$100 per job | huatplumbing.sg |
| Prima Technologies Pte. Ltd. (Prima Services) | Toilet Bowl Choke Clearing | From S$100 per job | primaservices.sg |
| Sk Plumber | Toilet bowl choke clearing | From S$115 per job | sksplumber.com |
| Best Plumbing | Clogged toilet bowl / Clearing toilet bowl choke | From S$120 per job | bestplumbing.com.sg |
| Summer Plumbing Service | Clogged toilet bowl / Clearing toilet bowl choke | From S$120 per job | sgplumbing.com.sg |
| NILE Plumbing | Clear Choke (Sink/Basin) | From S$150 per job | nileplumbingsg.com |
| Siam Engineering Pte Ltd | Choke Clearing & Drainage | S$150 per job | siamengineeringsg.com |
22 companies publish a choke clearing rate. Their published rates run from S$50 to S$150 per job, with S$80 in the middle: the two middle companies both print S$80, so it is a real published rate. The scope as printed is to clear one choke in a toilet bowl, floor trap or sink. Most lines name a toilet bowl or floor trap; the two that name a sink are printed as from S$50 per job and from S$150 per job. Many are "from" prices, so ask what the final price depends on.
Compare companies for choked drain clearing.
When the trap itself needs replacing
Clearing does not fix a trap that is cracked or leaking: it needs replacing. PUB's Plumbing Works page lists installing, replacing or removing any washbasin or sink, including the bottle trap or fitting trap below it, as simple plumbing works. That means a handyman may replace a sink's bottle trap without a PUB licence.
FROM THE HOMEZYPRO DIRECTORY
Published bottle trap replacement rates
For the most common unit (per job), the lowest published bottle trap replacement rates from 10 companies run from S$40 to S$100 per job (middle rate S$50), to replace one kitchen sink trap. The middle figure is a real published rate, not an average.
See 10 published bottle trap replacement rates and sources
| Company | Service as listed | Rate | Source |
|---|---|---|---|
| Plumber - Singapore Plumbing 24hrs | Supply & Replace Water Trap for Kitchen Sink | From S$40 per job | singaporeplumbing24hrs.com.sg |
| GD Plumbing | Replace bottle trap for kitchen sink | From S$50 per job | gdplumbing.com.sg |
| Home Plumbers Singapore | Supply and replace a kitchen-sink bottle trap | From S$50 per job | homeplumbers.com.sg |
| SG1 Plumber Singapore | Sink Bottle Trap Replacement | S$50 per job | sg1plumber.com |
| Sin Plumbing Singapore | Supply & replace bottle trap for kitchen sink | From S$50 per job | sinplumbing.com |
| Uncle Plumber | Supply and Replace bottle trap for kitchen sink | From S$50 per job | uncleplumber.sg |
| Kiasu Plumber | Supply & install bottle trap (kitchen sink) | From S$80 per job | kiasuplumber.com |
| Best Plumbing | Supply & replace bottle trap for kitchen sink | From S$100 per job | bestplumbing.com.sg |
| SR Power Plumber Pte. Ltd. | Supply & replace bottle trap for kitchen sink | From S$100 per job | srpowerplumber.com |
| Summer Plumbing Service | Supply & replace bottle trap for kitchen sink | From S$100 per job | sgplumbing.com.sg |
10 companies publish a bottle trap replacement rate. Their published rates run from S$40 to S$100 per job, with S$50 in the middle: the two middle companies both print S$50, so it is a real published rate. The scope as printed is to replace one kitchen sink trap. Most lines mention supplying the trap, but not all do, so ask whether the price includes the new trap.
If water is leaking under the sink and the trap looks sound, see kitchen sink leaking underneath for other places to check.
Habits that prevent sink chokes
HDB's floor trap guide says not to pour cooking oil or discard food waste and solid items down the floor trap or sink. It also says to use a degreaser on the kitchen sink discharge pipes regularly. HDB's guide to ceiling leaks suggests using a sink strainer.
In practice:
- Keep cooking oil out of the sink.
- Scrape food waste into the bin before you wash up.
- Keep a sink strainer in the plughole and empty it often.
- Use a degreaser on the discharge pipes regularly, following the product label.
Never mix cleaning products. The guide on mixing cleaning products explains why.
NEXT STEP
See plumbing companies in the directory with their published prices, the areas they say they cover and their sources.
Compare plumbersWhen to stop and call a professional
Stop and get help if:
- Water still will not drain after the trap is clear.
- The nearby floor trap overflows too.
- There is a leak under the sink.
- Neighbours have the same problem.
For serious floor trap chokes, HDB's floor trap guide says to engage a licensed plumber. HDB's guide to pipes says you maintain the sanitary branch pipes in your flat, while the Town Council maintains the main sanitary pipes.
See floor trap choke cost, plumbing costs and plumbing companies to compare.
Questions
Can I use boiling water to clear a sink choke?
This guide does not recommend it. HDB's guide to sinks and wash basins gives a different method: twist off the lower section of the bottle trap, remove the solid matter, flush it with water and screw it back on. If the sink still will not drain, call a licensed plumber.
Should I use a chemical drain cleaner?
Not as a first step. Clear the bottle trap first, following HDB's method, and never pour chemicals in to force the choke or mix cleaning products. HDB's floor trap guide suggests a degreaser on the kitchen sink discharge pipes regularly, as routine care to prevent chokes, not to clear one.
Does a plunger work on a kitchen sink?
HDB describes a plunger for toilets, not sinks, so start a sink choke at the bottle trap. For a toilet that drains slowly, HDB's guide to water closets says to place a plunger over the waste hole and pump vigorously. If your sink still will not drain once the trap is clear, call a licensed plumber.
Why does my sink choke keep coming back?
Because grease and solid waste are still getting into the drain. HDB says chokes come from solid matter or hardened grease, and its floor trap guide says not to pour cooking oil or discard food waste down the sink. Use a sink strainer. If chokes keep returning, ask a licensed plumber to check the pipe.
Can a handyman replace a bottle trap?
Yes. PUB's Plumbing Works page lists installing, replacing or removing any washbasin or sink, including the bottle trap or fitting trap below it, as simple plumbing works, which a handyman may do without a PUB licence. Regulated plumbing work outside that list needs a PUB Licensed Plumber. Ask whether the price includes the new trap.
Who clears a choke in the main pipe?
In an HDB flat, the Town Council does. HDB says the Town Council is responsible for maintaining the main sanitary pipes, while you maintain the sanitary branch pipes in your flat. For a choke in your own branch pipe or trap, call a licensed plumber.
- HDB says
- PUB's Plumbing Works page
- its floor trap guide
- HDB's guide to ceiling leaks
- HDB says
- HDB's guide to water closets
Prices come only from the sourced company rates in the HomezyPro directory, shown with each company and its source.
Practical guidance for planning a home job in Singapore. Company prices come from the HomezyPro directory, each linked to its source; rules and safety points link to the agency or manufacturer that sets them. This is not a site inspection, a quote or professional advice for your home.
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