Blocked Toilet: What to Do, What to Avoid, When to Call

Blocked toilet: stop flushing, close the toilet's water valve, then try a proper toilet plunger or a bucket of very hot water with washing-up liquid. Avoid acid and wire hangers. If the water still will not go down, if it comes up elsewhere, or if the blockage keeps coming back, call a plumber.

Blocked toilet or backed-up drain in Paris or the inner suburbs? Call +33 1 89 70 15 36 (01 89 70 15 36 from a French phone), 7 days a week, 24 hours a day, or write to us through the contact page or WhatsApp. Many of our plumbers speak English. Our drain unclogging service comes with equipment suited to old buildings.

In a Paris building, a blocked toilet is not a minor incident: waste pipes are often old, narrow and shared with your neighbours. Here is how to handle it without making it worse, and how to stop it happening again.

First steps when the toilet is blocked

1. Stop flushing. If the water has not gone down, another flush will not help. You risk an overflow, and water damage in the flat below.
2. Close the toilet's water supply (the small valve on the side or under the cistern), or the main stopcock if you cannot find it.
3. Protect the floor with cloths or newspaper.
4. Stop using other drains if water comes up in the shower or sink: the blockage is further down, in a shared section.

Why toilets block

In Paris, three cases come up most often.

• A paper blockage. Too much toilet paper, or wet wipes, even "flushable" ones, which do not break down fast enough for old pipes. They form a compact mass in the bowl's trap or the first bend.
• A dropped object. The toilet block hanging on the rim falls in and wedges in the trap. Do not push it with the brush: you would send it further down, and the bowl would then have to come off.
• Limescale. Paris water is hard. Over the years, scale narrows the waste pipes until the smallest amount of paper blocks them. A plunger is useless here: the pipe needs cleaning.

Home fixes that sometimes work

• A plunger. Use a flanged plunger made for toilets. Press it over the outlet, then push and pull to break up the blockage. Watch out for splashes.
• Very hot water and washing-up liquid. Pour in a good squirt of washing-up liquid, then a bucket of very hot, not boiling, water from a little height. Heat and weight sometimes break up a paper or grease blockage.

If nothing moves after two or three attempts, stop: the blockage is too dense or too far down.

3 mistakes never to make

Flushing again and again

The shortest route to an overflow.

Pouring acid or chemical drain cleaner

Hydrochloric acid can cause serious burns and toxic fumes. In an old building it attacks the joints, sometimes lead or cast iron, and causes leaks. And the acidic water left standing also burns the plumber who comes next. Chemical drain cleaners in general damage old pipes without shifting a wet-wipe blockage.

Using a wire coat hanger

It scratches the bowl's enamel for good and can pierce the flexible waste pipe, often fragile plastic, behind the toilet.

Blocked sink, shower or basin

The signs: slow draining, gurgling pipes, smells coming up, then water backing up or overflowing. The same rules apply: stop using the fixture, avoid chemicals, do not take anything apart unless you know how to put it back.

• Shower and basin: almost always hair and soap. Remove what you can see in the drain, then unscrew and clean the trap, with a bucket underneath.
• Kitchen sink: grease and food scraps. Try a plunger on the sink (blocking the overflow), then clean the trap.
• Several fixtures at once: if water comes up in the shower when you empty the sink, or several flats are affected, the blockage is in the shared drain stack. That is a job for a professional, and often for the building's property manager (the syndic).

A sewage smell without a clear blockage often has another cause: our article on why a bathroom smells like sewage helps you find it.

When to call a plumber straight away

• The toilet is completely blocked and unusable, especially if it is the only one.
• Waste water backs up into the shower, bath or sink.
• Water is overflowing or about to leak into the flat below.
• The blockage resists the plunger after several attempts.
• A hard object is stuck in the bowl.

If water has already reached a neighbour, our guide water leak: when to call a plumber urgently explains what to do.

What the plumber does

1. Diagnosis: where the blockage is (bowl, bend, stack) and what it is made of (paper, wipes, object, grease, scale).
2. Mechanical unblocking: a hand pressure pump, which sends a surge of water to push the blockage out with no chemicals, or a drain snake, a flexible spiral cable that breaks up the blockage far down the pipe.
3. Hydro-jetting for heavy cases: a high-pressure water jet cleans the whole pipe wall, scale included. The solution for a clogged building stack.
4. Camera inspection if the blockage keeps coming back or the pipe's condition is in doubt.
5. Removing the bowl if a hard object blocks the trap: the plumber takes out the object and refits the toilet with a new seal. Our toilet installation and replacement service takes over if the bowl needs replacing.

You are told the price before the work starts. For a rough idea, see our prices.

A toilet that keeps clogging: a structural cause

A one-off blockage is fixed for good. A toilet that blocks again a few days after every unblocking points to a cause a plunger will never solve:

• not enough slope on the waste pipe, badly done in past works or sagging over time: waste sits instead of flowing away;
• a narrowed pipe after years of scale and deposits;
• a weak flush, badly adjusted or faulty, that no longer releases enough water;
• tree roots in a buried pipe, for a ground floor or a house;
• a shared section of waste pipe serving several flats, with a fault that looks private but is not;
• an original design fault in an old building: undersized pipe or insufficient slope from the start.

The right approach: a camera inspection. Fed into the pipe, it shows its real condition: slope, deposits, cracks, roots, faulty joints. A properly equipped plumber shows you the images, so you understand the cause and can approve the fix: high-pressure cleaning, correcting the slope, replacing a section, a new flush mechanism. Repeated unblocking often ends up costing more than a diagnosis followed by a proper repair.

In a co-ownership building: if other flats have the same problem at the same time, the cause is probably in the common parts. Tell the syndic, who will have it fixed once for the whole building. Our article on plumbing in co-ownership buildings explains who does what.

10 habits to prevent blocked drains

1. Fit a hair catcher on the shower drain and empty it often.
2. Never pour grease down the sink. Let it set and put it in the bin. Wipe pans with paper before washing them.
3. No wet wipes in the toilet, even "flushable" ones. Only toilet paper goes in the bowl.
4. Rinse sinks with very hot water every week, but no boiling water on PVC pipes.
5. Baking soda and white vinegar once a month: a few spoonfuls of baking soda, a glass of vinegar, then rinse with hot water after a while. Gentle on seals.
6. Clean the traps a few times a year, with a bucket underneath.
7. Avoid chemical drain cleaners for routine care: caustic soda damages pipes and seals over time.
8. Keep a bin in the toilet for cotton buds, sanitary products and wipes.
9. Have old, scaled pipes cleaned now and then: preventive hydro-jetting scours the walls before a blockage forms.
10. Act on the first signs: slow draining, gurgling, smells. A partial blockage is easier to clear than a complete one.

• Shower. Main culprit: hair and soap. Priority habit: hair catcher.
• Kitchen. Main culprit: grease and scraps. Priority habit: grease in the bin, hot water.
• Toilet. Main culprit: wipes, sanitary products. Priority habit: a dedicated bin.
• Basin. Main culprit: hair, toothpaste. Priority habit: clean the trap.

FAQ

How many unblockings before having the pipe inspected?

If the blockage comes back more than twice in a few weeks despite a successful unblocking each time, move to a camera diagnosis.

Does caustic soda unblock a toilet?

It can dissolve a grease blockage, but it is corrosive, damages old pipes and seals, and does nothing against wipes or an object. It also makes the plumber's job harder. Better to avoid it.

Who pays for unblocking, the tenant or the landlord?

A blockage caused by everyday use of the flat is usually the occupant's responsibility. A blockage in a shared stack falls to the co-ownership. A structural fault in the installation is a matter for the landlord. If in doubt, ask the plumber for a written note saying where the blockage was.

Can a toilet that keeps blocking damage the pipe?

Yes. If the cause is not treated, the problem gets worse, especially with roots that keep growing or deposits that keep building up.

Blocked toilet with standing water in the bowl: what should I do?

Stop flushing and close the toilet's water valve. If the level is high, bail some of the water into a bucket with a small container, wearing gloves, so you can use the plunger without an overflow. Water that goes down very slowly points to a partial blockage, often paper or wipes, which a plunger can shift. Water that does not move at all, or rises when a neighbour uses their bathroom, points to a blockage further down the pipe: stop there and call a plumber.

How can I tell if the toilet pipe itself is blocked?

Several signs point to the pipe rather than the bowl: the shower or basin drains slowly at the same time, you hear gurgling when you flush, water comes up in another fixture, or the blockage returns a few days after a successful clear. In that case a plunger is not enough: the plumber uses a drain snake or high-pressure jetting, then inspects the pipe with a camera if the problem keeps coming back. If the blockage is in the building's shared stack, tell the building manager (syndic) too.

Get your toilet or drain unblocked

Réseau Tubulure works in Paris and the inner suburbs (92, 93, 94), 7 days a week, 24 hours a day, on blocked toilets, backed-up drains and blockages that keep coming back. Many of our plumbers speak English.

• Phone: +33 1 89 70 15 36 (01 89 70 15 36 from a French phone)
• Form: contact us
• WhatsApp: from the button on the site

See our drain unclogging service.