DIY GUIDE · PLUMBING & HEATING · CHECKED OCTOBER 2026
How to unblock a sink, toilet or drain yourself
Minutes to an afternoon. £20–£40 for a plunger and a set of rods you keep.
Start at the plughole, work outwards, and stop at your boundary. Plunger, trap, rods — chemicals last.
- Every step, start to finish
- Checked October 2026 — sources at the end
- Honest about when to call a pro
FIRST, THE HONEST ANSWER
Do it yourself, or get a plumber?
Do it yourself if…
- One fitting is slow or blocked and the others in the house drain normally
- The blockage is in a trap, a toilet's U-bend or a gully you can reach
- There is an inspection chamber in your garden whose cover you can lift, and it serves only your house
- You are happy dealing with dirty water and wearing gloves and glasses
Get a pro if…
- Several fittings back up at once, or the toilet bubbles when the bath empties
- Water is coming up out of a gully or a manhole, or sewage is in the garden
- Rods meet something solid that will not move, or bring back roots or broken pipe
- The chamber is shared with neighbours, deep, or under a public pavement
Safety first
- Wear rubber gloves and safety glasses for every blockage. Waste water carries bacteria, and plungers and rods splash.
- Do not mix drain products, and never plunge, rod or open a trap after pouring a chemical in. HSE's guidance on hazardous substances is to know what a product does before you use it; drain unblockers are strong acids or alkalis that burn skin and eyes.
- Inspection chamber covers are heavy and can trap fingers. Lift with a proper key or a bolster, bend your knees, slide the cover rather than carry it, and never leave an open chamber unattended.
- Do not climb into a manhole or put your head into one. Sewer gases collect in chambers and they are dangerous.
- Wash hands and forearms thoroughly afterwards, and disinfect the rods, the plunger and any surface that waste water touched.
Stop here: Stop here: shared sewers, collapsed pipes and anything you would have to dig
Since 1 October 2011 in England and Wales, shared private sewers and the lateral drains outside a property's boundary belong to the water and sewerage companies, who clear and repair them; the drain within your boundary that serves only your home stays yours. In Scotland and Northern Ireland the public sewer is likewise the sewerage provider's. Report a blockage that is not yours to the company on your water bill instead of rodding it. New or altered drainage, including digging out and replacing a broken pipe, falls under Part H of the Building Regulations in England, with Wales, Scotland and Northern Ireland applying their own building regulations. Entering a manhole or chamber is a confined space with the danger of sewer gas, and it is not householder work. How to hire a drain unblocker →
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Disinfectant | For the tools and any surface waste water touched | Enough for a bucket |
| Washing soda or hot water | For a slow kitchen sink after the solids are out | A kettle of hot water, not boiling |
| Chemical unblocker | Only for a slow drain, and only after reading the label | One dose, if at all |
| Bin bags | For what comes out of a gully or a trap | Two |
How many rods you need
Rod length needed = the distance between the two chambers, plus a metre to work with. If the chamber by the house is 6 m from the next one, you need 7 m of rods; a set of eight 0.9 m rods reaches.
Pace it out across the garden from cover to cover. If the next chamber is beyond your boundary, that length of drain may be a shared sewer and not yours to rod.
A flat cup plunger seals over a sink, bath or shower plughole. A flange plunger has an extra soft rubber collar that fits into a toilet's outlet and seals there. Using a sink plunger on a toilet pushes water past it and achieves little. If you buy one, buy the flanged kind; the collar folds back to work as a cup.
Drain rods are flexible sections that screw together, with a worm screw for breaking up blockages and a rubber plunger head for pushing them. Sets typically make up several metres. Choose a set with both heads. Turn the rods clockwise only as you push and pull them; turning them the other way unscrews the joints and leaves a rod in the drain.
A thin spring or plastic hook is the tool for hair in a bath or shower waste and for the bend under a basin. It reaches past the trap where a plunger cannot push. It is not stiff enough for an outside drain.
Liquid unblockers work by dissolving organic matter and are strong acids or alkalis. They can damage some metals and finishes, and they make every mechanical method dangerous afterwards because the trap is then full of chemical. Use one only on a slow drain, never a fully blocked one, and only after reading the label and the hazard symbols.
Most kitchen blockages are fat, oil and grease poured hot that set in the pipe. Most bathroom ones are hair. Most toilet ones are wipes. A sink strainer, a hair catcher in the shower and a bin by the toilet stop most blockages before they start.
THE PART THAT DECIDES THE FINISH
Before you start — where the blockage is
Find where the water stops, and you have found the blockage. Match what you see to one of these and start there.
One basin, bath or shower slow
The blockage is in the waste or the trap under it.
- Pull hair out of the plughole with a plastic hook or a drain spring
- Cover the overflow with a wet cloth, then plunge the plughole hard ten or twelve times
- If it is still slow, unscrew the bottom of the bottle trap into a bowl and clean it
- Run hot, not boiling, water to test
Kitchen sink blocked
Usually fat and food in the trap or the first length of pipe.
- Scoop standing water into a bucket so you can see the plughole
- Plunge with a cup plunger, blocking the second bowl's plughole or the overflow with a cloth
- Undo the trap into a bowl and clean out the solids
- If an appliance hose joins the trap, check its spigot is clear too
Toilet not flushing away
A blockage in the U-bend or just past it.
- Do not flush again; it may overflow
- Bail out some water so the bowl is about half full
- Push a flange plunger into the outlet and plunge firmly, keeping it submerged
- If water drains but slowly, flush once with the lid down and see if it clears
Outside gully or inspection chamber full
The blockage is in the drain beyond the house.
- Lift the cover of the chamber nearest the house and look: full means the blockage is downstream, empty means upstream
- Check whether the chamber serves only your house; if it collects neighbours' drains it is a shared sewer
- Clear leaves and silt from a gully by hand, wearing gloves
- Rod from the chamber that is full towards the next chamber downstream
THE JOB
How to clear the blockage
Set up and find the blockage
10 minRead the cards above and decide where the water stops. Check other fittings: if only one is slow, the blockage is near it; if the downstairs toilet bubbles when the bath empties, it is further down. Put on gloves and glasses, put towels round the fitting, and have a bucket ready. Tell the household not to run water or flush while you work.
- Run a tap elsewhere in the house; if that drains fine, the problem is local
- Check the outside gully first after heavy rain; leaves block it more often than anything inside
- Have a torch for looking into chambers and traps
Mistake to avoid: Pouring a chemical in first. Every later method then splashes chemical, and a full blockage just sits under a pool of it.
Clear what you can see
10 minThis is the first prep line in your card above. Pull hair out of a bath or basin waste with a plastic hook or drain spring. Scoop food and fat out of a kitchen plughole. Clear leaves and silt from an outside gully by hand into a bin bag. A surprising number of blockages end here.
- Lift out a click-clack or pop-up plug to reach the hair wrapped round it
- Twist a drain spring slowly as you feed it in, then pull it back with what it has caught
- Run water after each clear to see if it has worked
Mistake to avoid: Pushing a visible blockage further down with a hook. Pull it towards you and out, not away into the pipe.
Plunge the sink, bath or shower
10 minLeave a few centimetres of water in the basin so the plunger cup is covered. Block the overflow with a wet cloth held firmly, and block any second plughole. Set the cup over the plughole, push down gently to expel the air, then pump hard up and down ten or twelve times without breaking the seal. Pull it off sharply on the last stroke.
- The overflow must be sealed or the pressure escapes through it
- A smear of petroleum jelly on the cup rim improves the seal
- Repeat two or three times before moving on
Mistake to avoid: Plunging with the overflow open. The water just moves in and out of the overflow and the blockage never feels the pressure.
Clean the trap
20 minPut a bowl under the trap. Unscrew the bottom of a bottle trap, or the two nuts of a tubular trap, by hand, and tip the contents into the bowl. Clean the inside with an old brush and look into the pipe beyond it. Refit hand tight with the washers in place and run water to test for both flow and drips.
- Check each washer is seated and not folded before tightening
- Look into the pipe towards the wall with a torch; a plug of fat there needs a drain spring
- Hand tight is enough on plastic; tools crack the nuts
Mistake to avoid: Losing a trap washer in the bowl of dirty water. Fish it out before you tip the bowl away, or the trap drips when refitted.
Plunge the toilet
15 minBail the bowl to about half full. Push the flanged plunger into the outlet so the collar seals, and plunge firmly with steady strokes, keeping the plunger under water so you push water, not air. When the level drops suddenly, it has cleared. Pour a bucket of water into the pan from a height to check before you flush.
- Push the first stroke gently; a hard first stroke splashes back
- Keep the lid and seat up and towels round the base
- Test with a bucket, not the flush, so an overflow is only a bucketful
Mistake to avoid: Flushing repeatedly to force a blockage. Each flush adds a cistern of water, and the next one comes over the rim.
Open the inspection chambers
15 minLift the cover of the chamber nearest the house with a manhole key or a bolster, keeping your fingers clear. If it is full, the blockage is downstream; lift the next cover along. If it is empty and the gully by the house is full, the blockage is between the two. Work out whether the chamber serves only your house: count the pipes coming in.
- Slide covers aside on the ground rather than lifting them high
- Put a board or a bright object over an open chamber if you step away
- If pipes from neighbouring houses join in the chamber, the drain beyond is likely a shared sewer
Mistake to avoid: Rodding a shared sewer yourself. Beyond your boundary, or where neighbours' drains join, the sewerage company is responsible, and they clear it.
Rod the drain
45 minScrew two rods together with the worm screw on the end, and feed them into the full chamber's outlet, towards the blockage. Add rods as you go, turning them clockwise only while you push and pull. When you feel resistance, work the rods back and forth to break it up, then swap the worm for the plunger head and push. A sudden rush of water means it has cleared. Pull the rods back, still turning clockwise.
- Never turn anticlockwise; the joints unscrew and a rod stays in the drain
- Hose the rods down as they come out, into the chamber
- If the rods meet something hard that will not move, stop: that is a collapse, a root or a broken pipe
Mistake to avoid: Turning the rods anticlockwise to free a snag. The rod you cannot see unscrews, and recovering it needs a drain engineer.
Flush through and clean up
20 minRun plenty of water through the cleared fitting or drain for a few minutes. Watch the chambers drain freely. Replace the covers, seating them properly. Disinfect the rods, plunger, bowl and any surface that waste water touched, and bag the debris from the trap or gully.
- Run hot water and washing soda through a kitchen drain once the fat is out
- Hose the gully grid and refit it
- Wash your hands and arms thoroughly even if you wore gloves
Mistake to avoid: Leaving a chamber cover not quite seated. It rocks, breaks, or tips someone into the chamber.
The mistakes that show
- Reaching for chemicals before a plunger or the trap
- Plunging with the overflow open
- Flushing a blocked toilet again and again
- Turning drain rods anticlockwise
- Rodding a shared sewer that the sewerage company should clear
Stop here and get a drain engineer
- Several fittings are backing up at once, or the downstairs toilet bubbles when other water runs
- Sewage is coming up in the garden or out of a gully or chamber
- Rods hit something hard, or bring back roots, soil or bits of pipe
- The blockage is in a chamber shared with neighbours or beyond your boundary
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| Sink still slow after plunging | The blockage is past the trap. Undo the trap, clean it, and feed a drain spring into the pipe towards the wall. If that fails, the blockage is further down. |
| Toilet drains slowly but doesn't overflow | A partial blockage in the U-bend, often paper or a wipe. Plunge with a flanged plunger, then test with a bucket of water from a height. |
| Gurgling from the plughole | Air being drawn through the trap by a partial blockage or a long pipe run. Clear the trap; if it persists, a resealing trap or an air admittance valve is the fix, which is plumbing work. |
| Bad smell from the drains | A dry trap, fat in the pipe, or a blocked gully. Run water into every rarely used fitting, clean the kitchen trap, and clear the outside gully. |
| Water backing up in the shower tray | Hair in the shower waste. Lift the grate and the trap's dip tube and pull the hair out with a hook. |
| Manhole full of water | The blockage is downstream of that chamber. Lift the next cover; if that one is empty, rod between them. If the next one is a neighbour's or outside your boundary, call the sewerage company. |
| Rods stuck in the drain | Usually because they were turned anticlockwise and a joint unscrewed. Do not pull hard. A drain engineer can recover them. |
| Blockage keeps coming back | Fat build-up, roots, or a sagging pipe that collects debris. A CCTV survey shows which, and that is a drain engineer's job. |
WHAT YOU SAVE
What it costs to do it yourself
| Flange plunger | £4–£10 |
|---|---|
| Set of drain rods with heads | £16–£30 |
| Chemical unblocker, if needed | £7–£14 |
| Total, plunger and rods | £20–£40 |
| DIY total | £20–£40 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
Against a drain engineer's guide price, a plunger and rods pay for themselves on the first blockage; the engineer earns their fee on the blockages that need a jetter or a camera.
RATHER NOT?
Drain unblockers near you, with prices shown
The ones who cover your area, nearest first, with one score from every review. No account needed to look.
Or post the job free and let them come to you.
Disinfect the plunger and rods, rinse them, and let them dry before bagging them. Store them outside, away from food.
Wipe greasy pans with paper before washing them, put a strainer in the kitchen sink and a hair catcher in the shower, and keep a bin by the toilet for wipes.
Bag solids from traps and gullies into general waste. Never pour cooking fat down the sink: let it set and bin it. Leftover chemical unblockers are hazardous; take them, in their original container, to your council's household waste recycling centre, which accepts household chemicals. Find yours on the council website or the recycling pages for your nation.
Sketch the covers on a plan of the garden. Next time you will know where to look and which ones serve only your house.
Unblocking a sink, bath, toilet or outside drain: questions people ask
Clear what you can see, then plunge with the overflow blocked by a wet cloth. If that fails, undo the trap into a bowl and clean it. Chemicals are a last resort and make every other method dangerous.
Bail it to half full, then use a flanged plunger pushed into the outlet, plunging steadily under water. Test with a bucket of water from a height before flushing.
You are responsible for the drain within your boundary that serves only your home. In England and Wales, shared sewers and lateral drains beyond the boundary transferred to the water and sewerage companies on 1 October 2011; report those blockages to the company on your water bill.
Clockwise only, both pushing in and pulling out. Turning them anticlockwise unscrews the joints and leaves a rod in the drain.
They are strong acids or alkalis. Read the label, wear gloves and glasses, never mix products, and never plunge or open a trap after using one. Use them only on a slow drain.
Locufy's UK price guide puts drain unblocking at £80–£250 per job, typically £180 — the same three figures as the strip at the top of this page.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- Flat-bottom basin bottle trap installation instructions — trap layout and cleaning access
- HSE — COSHH basics: hazardous substances
- HSE — manual handling at work
- gov.uk — transfer of private sewers to the water companies from 1 October 2011 (England and Wales)
- Brentwood Borough Council — drain and sewer blockages: what is yours and what is the water company's
- gov.uk — Approved Document H: drainage and waste disposal (England)
- gov.uk — recycling collections: find your council (England and Wales)
- mygov.scot — find your council's recycling centre (Scotland)
- nidirect — recycling and reusing (Northern Ireland)
- B&Q — price check: plungers
- B&Q — price check: drain rods
- B&Q — price check: drain unblockers