Intro

On most jobs, blocked sinks waste time and kill your schedule. A very smart plumber shared a trick that clears most clogs fast, without removing the trap. You use a wet/dry vacuum, seal the drain tight, and pull the blockage in under 5 minutes. It works on kitchen sinks, basins, and baths with overflows. In this guide, I’ll show you the exact kit, the sealing method, and the steps. I’ll also explain when not to use it, and how to stop clogs coming back. Simple, safe, and fast.

Quick Answer

A very smart plumber shared a trick: use a wet/dry vacuum to suck out sink clogs. Seal the plughole and overflow, run the vac in 20–30 second bursts, and flush 3–5 litres of hot water. Most jobs take 3–7 minutes, with no trap removal or chemicals.

Table of Contents

• Why A Very Smart Plumber Shared a Trick Works
• Tools You Need
• Step-by-Step: Use the Vacuum Trick
• When Not to Use It
• Prevent Future Clogs
• For Pros: Speed, Pricing, and Small-Job Wins

Key Takeaways

• Most clogs clear in 3–7 minutes with a wet/dry vacuum.
• Seal both the drain and overflow—2 points—to get full suction.
• Use 20–30 second bursts, 2–4 times, then flush 3–5 litres.
• Protect traps: don’t exceed gentle suction; avoid chemical residues.
• If the pipe stays blocked past 5–10 metres, switch to a snake.

Why A Very Smart Plumber Shared a Trick Works

This method uses negative pressure to move the blockage towards you. Hair, soap scum, and food sludge loosen fast when suction hits both the drain and the overflow. On most sinks, the trap is 32 mm or 40 mm. That small bore makes snakes snag. The vacuum trick clears the bore evenly, so you don’t damage the trap or the seal. It also keeps the floor dry. No trap off, no bucket, no mess.

Tools You Need

• Wet/dry vacuum (10–20 litres is ideal)
• Duct tape or a heavy cloth (to seal the overflow)
• A rubber bung, plunger head, or a wrapped rag (to seal the plughole)
• Nitrile gloves and eye protection
• 3–5 litres of hot water for flush
• Optional: a 1–2 metre length of flexible hose adaptor

Tip: If your vac has a 35 mm or 38 mm hose, it matches many overflow inlets. A simple rubber cone adaptor helps seal odd sizes.

Step-by-Step: Use the Vacuum Trick

1. Check Safety First

• Ask the client if any chemicals were poured in. If yes, don’t vacuum. Neutralise or flush first, or use a mechanical snake instead.
• Unplug any under-sink electrics. Wear gloves and eye protection.

2. Prep the Area

• Remove the plug and any basket strainer.
• Wipe the rim dry so tape sticks.
• Block the overflow: press a cloth into the opening and tape it tight. You need an airtight seal.

3. Make a Tight Seal at the Drain

• Fit a rubber bung, a plunger cup, or a well-wrapped rag into the plughole.
• Poke a hole just large enough for the vac hose. Smaller hole = stronger suction.

4. Set the Vac to Wet Mode

• Ensure the filter is for wet use.
• Keep the vac base on a flat surface. Have 1–2 litres capacity free to catch murky water.

5. Pull the Clog (20–30 Second Bursts)

• Hold the hose firmly. Switch on for 20–30 seconds.
• Stop. Listen. You’ll often hear a “slurp” as water moves.
• Repeat 2–4 times. Don’t overdo it. Gentle cycles protect seals.

6. Flush and Test Flow

• Pour 3–5 litres of hot water down the drain.
• Time the flow: 2 litres in 10–12 seconds is healthy for a basin. Kitchens often push 12–18 litres per minute with a good mains feed.

7. Final Checks

• Look for leaks at the trap joints. Tighten compression nuts a quarter-turn if needed. Use PTFE tape on threads only if they were disturbed.

Total job time is usually 3–7 minutes. Heavier kitchen grease may take 8–10 minutes.

When Not to Use It

• Chemical Risk: If strong caustic or acid cleaners were used, don’t vacuum.
• Collapsed or Frozen Pipes: If a section is crushed or frozen, suction won’t help.
• Long-Run Blockages: If the clog sits 5–10 metres away, use a snake or jetter.
• Loose Traps: If the trap moves by hand, reseat it first. You need a firm, sealed system.
• Toilets: Don’t use a vacuum directly on a toilet pan. Use a flange plunger or closet auger.

Prevent Future Clogs

• Hot Flush: Once a week, run 2–3 litres of hot (not boiling) water with a squeeze of washing-up liquid. It lifts fats and soap film.
• Mesh Strainer: Fit a 1–1.5 mm mesh at kitchen sinks to catch rice and pasta.
• Grease Discipline: Wipe pans with a paper towel before washing. It takes 10 seconds and saves blockages.
• Trap Angle: Keep trap arms level with a slight fall—about 3 mm per 300 mm. Too much fall strips the water seal; too little builds sludge.
• Overflow Clean: Every 3–6 months, backflush the overflow with warm water. Hair collects there.

For Pros: Speed, Pricing, and Small-Job Wins

On site, time is money. This method saves 30–40 minutes compared with pulling a 40 mm kitchen trap and rodding. It also leaves no tool marks on chrome or ceramic. Many contractors price quick sink clears as a fixed fee with a 30-minute cap. If you hit 25 minutes without a result, tell the client you’ll switch to a snake or book a jetter. Clear expectations prevent disputes.

If you’re also looking to streamline professional proposals, our guide covers how to turn quick service calls into tidy, branded quotes. This pairs well with understanding project timelines, so you can book follow-up works without gaps. And for admin time, check our advice on invoice templates that save time.

H2 add-on for SEO clarity: A very smart plumber shared a trick because it reduces callbacks. A clean, sealed vacuum pull clears the blockage and the overflow channel at the same time. That’s why repeat clogs drop when you finish with a 3–5 litre hot flush.

FAQ

Can I use this on a bath or basin with an overflow?

Yes. It works well. Just seal the overflow fully with a cloth and duct tape. Then seal the drain and run the vacuum in 20–30 second bursts. Flush with 3–5 litres of hot water after.

Will the vacuum damage the trap or seals?

Not if you seal well and use short, gentle bursts. Most traps are 32 mm or 40 mm and handle this easily. Avoid long continuous suction. Check for drips and nip compression nuts a quarter-turn if needed.

What size vacuum do I need?

A 10–20 litre wet/dry unit with a 35–38 mm hose works great. Smaller handheld vacs rarely seal well. Ensure the filter is set for wet mode so it won’t clog.

How long should I run the vacuum?

Use 20–30 second bursts, 2–4 times. Total active suction is often under 2 minutes. If there’s no change after 3–4 cycles and a hot flush, switch to a snake.

What if the clog returns in a few days?

Do a hot flush routine: 2–3 litres of hot water weekly with washing-up liquid. Fit a mesh strainer. If it still returns, you likely have a long-run grease plug or a bellied pipe. Book a snake or jetter.

Conclusion

A very smart plumber shared a trick that saves time and avoids mess: seal the overflow and drain, use a wet/dry vacuum in short bursts, and finish with a hot flush. It clears most sink clogs in minutes and reduces callbacks. Next steps: 1) Add a rubber bung and tape to your kit. 2) Practise the seal technique on a test basin. 3) Offer a fast-fix price with a 30-minute cap. For admin, tools like Donizo help you turn quick wins into clean proposals and invoices in one flow. Use this method today and keep your day moving.