How to unblock a toilet without making things worse

First rule: stop flushing. Everyone does it. You press the handle, the water rises instead of falling, and some hopeful part of the brain says "one more go". One more go is how a blocked toilet becomes a wet bathroom floor and a stain on the kitchen ceiling below.

If the bowl is close to the rim, take the lid off the cistern and lift the float, or close the isolation valve on the pipe that feeds the cistern. On most toilets that's a small valve with a screwdriver slot, and a quarter turn shuts it. Now the water can't get any higher than it already is.

Good. The emergency is over. Now it's just a job.

Set up before you start

Five minutes of preparation saves an hour of mopping.

• Lay old towels or a split bin bag round the base of the pan.
• Put on rubber gloves, the long kind if you have them.
• Open a window.
• Have a bucket nearby. If the bowl is brim full, bail some out with an old jug until it's about half full. You need enough water to plunge with, not a paddling pool.
• Move the bath mat, the toilet roll and anything else you'd like to keep dry.

Step one: the plunger

A plunger fixes most toilet blockages. The catch is that a lot of people own the wrong one.

Flange or cup

A cup plunger is the simple rubber dome on a stick. It's designed for flat surfaces: sinks, baths, shower trays. On a toilet it can't seal against the curved outlet, so most of your effort just pushes water back up into the bowl.

A flange plunger has an extra soft rubber sleeve that folds out from inside the cup. The sleeve goes into the outlet at the bottom of the pan and makes a seal. That's the one you want. Some toilet plungers have a ribbed bellows shape instead; they work on the same principle. If a cup plunger is all you have, try it anyway, but don't expect miracles.

Technique

1. Make sure the cup is covered by water. Plunging air achieves nothing except splashing.
2. Put the flange into the outlet and lower the cup slowly, so the trapped air is pushed out gently. A sharp first push sprays the room.
3. Push down and pull back firmly, keeping the seal. The pull matters as much as the push. It's the back-and-forth pressure that loosens the blockage.
4. Do 15 to 20 strokes, then lift the plunger to break the seal and see whether the water drops.
5. Repeat for several rounds. Persistence beats violence here.

When the water finally drains with a satisfying gulp, don't test it with the cistern yet. Pour a bucket of water into the bowl from waist height. If that goes down cleanly, open the isolation valve, let the cistern fill and flush once, with your hand ready to close the valve again.

Step two: hot water and washing-up liquid

If plunging hasn't shifted it, or the water drains slowly but never quite clears, try this. It works best on blockages of paper and waste. It does very little to anything solid.

Squeeze a generous amount of washing-up liquid into the bowl, roughly a cupful. Then pour in a bucket of hot water: hot from the tap, or from a kettle that has been left to cool for a good while. Not boiling. A ceramic pan is cold, and boiling water poured into it can crack it. It doesn't do the plastic connector between the pan and the soil pipe any favours either.

Pour from waist height so the weight of the water helps. Leave it for 20 to 30 minutes, then plunge again.

Step three: the toilet auger

A toilet auger, also called a closet auger, is a length of spring steel cable inside a rigid tube, with a crank handle at the top and a bent end at the bottom. The bent end usually has a rubber or plastic sleeve to protect the porcelain. They're inexpensive, most DIY shops sell them, and they're the right tool for a blockage the plunger can't reach.

How to use one:

1. Pull the handle up so the cable retracts into the tube.
2. Put the bent end into the bowl with the sleeve resting against the bottom of the outlet.
3. Turn the crank and push down at the same time, feeding the cable round the trap.
4. When you feel resistance, keep turning. The cable will either break the blockage up or hook it.
5. Pull the cable back slowly while still turning. If it brings something with it, bag it.
6. Test with a bucket of water, as before.

An auger is also the best tool when something solid has gone in: a toy, a toothbrush, a deodorant cap. Plunging tends to push solid objects further into the trap, where they wedge. If you know something solid is down there, go straight to the auger, or to gloves and patience if you can see it.

What not to do

Toilets get damaged far more often by the cure than by the blockage.

• Don't pour chemical drain cleaner into a toilet. It can't reach a blockage through a full bowl of water, so it just sits there, and then someone has to plunge a bowl of caustic or acidic liquid. Splashback burns skin and eyes. Some products can also harm older pipework and septic tanks.
• Don't mix cleaning products. Bleach combined with acidic cleaners or ammonia gives off toxic gas. In a small bathroom with the window shut, that's a real hazard.
• Don't use a coat hanger. Bent wire scratches the glaze and leaves grey marks you'll be looking at for years. It doesn't reach far enough to help anyway.
• Don't use boiling water. A cracked pan is a much bigger job than a blocked one.
• Don't keep flushing to test it. Use a bucket, so you decide how much water goes in.
• Don't force drain rods through the pan. Rods are for drains, worked from a manhole, not for ramming through a ceramic trap.
• Don't plunge or chemically treat a macerator toilet. If there's a pump unit behind your toilet, follow its manual.

Wet wipes and the word "flushable"

Most toilet blockages in modern homes share a root cause: things that aren't toilet paper. Wet wipes lead the field. Toilet paper is made to fall apart quickly in water. Wipes are made not to, because nobody wants a wipe that disintegrates in their hand.

Some wipes carry a "flushable" label. Read it carefully. It tells you the wipe will disappear round the bend when you flush. It doesn't promise the wipe will break down in the pipes, and wipes collect in drains, snag on joints and bind with fat into solid lumps. What qualifies a product for the label varies by country and manufacturer. The rule many water companies repeat is the three Ps: pee, poo and paper. Everything else goes in the bin.

The rest of the usual suspects: cotton buds, sanitary products, nappies, cotton wool, dental floss, cat litter, cooking fat and kitchen roll. Kitchen roll catches people out because it looks like toilet paper. Wet, it's much tougher.

When the problem isn't the toilet

Sometimes the toilet is just the lowest, most visible point of a bigger blockage. Signs that the trouble is further down:

• Several fixtures are slow or backing up at once: bath, shower and basin as well as the toilet.
• Water rises in the toilet bowl when you drain the bath or the washing machine empties.
• Plugholes or the toilet gurgle when something else drains.
• There's a smell outside near the manhole or the gully.

If you see any of these, plunging the toilet will achieve very little. Check the inspection chamber instead: the manhole cover in the garden, path or drive. Lift it carefully. Covers are heavy, edges can be sharp, and fingers get trapped. Use a proper lifting key or two large flat screwdrivers, and lift with your legs.

Then look in:

• If the chamber is full of standing water or sewage, the blockage is downstream of it, further towards the sewer.
• If the chamber is empty, the blockage is between the house and that chamber.
• If there are several chambers, start with the one nearest the house and work outwards. The blockage sits between the last full one and the first empty one.

Clearing a main drain with hired rods is possible for a determined homeowner, but it's messy and unpleasant. In many places a drain shared with neighbours, or one beyond your boundary, is the water or sewerage company's responsibility rather than yours. The rules vary by country and region, so check before you pay anyone. Our blocked drains guides go into more detail.

Quick decision guide

• Water high in the bowl, only this toilet affected: plunge with a flange plunger.
• Drains slowly, only this toilet: hot water and washing-up liquid, wait, then plunge.
• Something solid went down: auger, or gloves. No hard plunging.
• Plunger and auger have both failed: the blockage is probably past the trap or in the pan connector. Time for a professional.
• Toilet, bath and basin all slow, or gurgling: lift the manhole cover.
• Manhole full: blockage downstream. Call a drainage professional, or the water company if it's a shared drain where you live.
• Macerator toilet: follow the manufacturer's instructions. No plunging, no chemicals.

When to get a drainage professional

Bring in someone with proper equipment when:

• An inspection chamber is full and you can't clear it safely.
• Blockages keep coming back. Repeat blockages often mean a cracked or sagging pipe, roots, or a badly fitted pan connector, and a CCTV drain survey will find which.
• Sewage is coming up inside, through a shower tray, a floor gully or a downstairs toilet.
• The pan is cracked, rocking, or leaking at the base.
• Something valuable went down and needs to come back up in one piece.

A drainage specialist brings a camera, powered rods or a jetter, and a decent idea of where your pipes actually run. That last one is worth more than it sounds.

Once the toilet is flowing again, check the rest of the bathroom. Basins clog more slowly and less dramatically, usually with hair and soap, and if yours is sluggish too, our guide on how to unblock a bathroom sink covers it without any of the above drama.