Blocked drain: what helps now
The water sits in the sink, the shower or the basin and drains slowly or not at all. Usually there were warning signs, but most people notice only when nothing moves any more.
This page tells you what you can do yourself, what is better left alone, and how to tell whether the problem sits at this one drain or further back in the pipework.
What you can do right now
These steps cost nothing and often stop a blockage from turning into water damage.
Do not add any more water
Stop using the affected drain. Switch off the dishwasher and the washing machine if they drain into the same pipe. Every litre that goes in now has to end up somewhere.
Do not pour in anything chemical
Liquid drain cleaners rarely dissolve a solid blockage. They sit on top of it, can attack seals and come back out when the pipe is opened.
Check how many drains are affected
Run water somewhere else in the building and watch. If everything drains normally there, the blockage probably sits close to the affected basin. If water backs up elsewhere too, it sits further back.
Look at the trap if only one basin is affected
The trap sits under the basin and that is where things collect most often. Put a bucket underneath, undo the fitting by hand and clear it out. If that is not for you, leave it.
Do not use force
No wire, no screwdriver and nothing hard down the pipe. That damages pipework, and ceramic basins crack easily. It turns a blockage into a repair job.
Clear the access
Empty the cupboard under the sink and move the washing machine, boxes and anything fragile out of the way. That saves the most time on site.
When to call us
- Several drains in the building are slow or blocked at the same time.
- Water comes back up in another drain as soon as you run water anywhere.
- The drain in the basement or lower floor is affected.
- There is a clear smell of sewage.
- The blockage happened before and has come back.
- You have already poured in a chemical drain cleaner and it did not help.
Where blockages usually come from
In the kitchen: fat and food waste
Fat goes down the drain as a liquid and sets again in the cold pipe. Together with food waste and coffee grounds it builds a layer that keeps growing and narrows the pipe.
Hot water helps against fresh fat and against the start of such a layer. It does nothing against old, hard deposits.
In the bathroom: hair and soap residue
In showers and basins, hair mats together with soap and cream residue into a solid plug. It almost always sits within the first half metre behind the drain.
A strainer in the drain solves this more permanently than anything poured in afterwards.
Further back: deposits, roots, foreign objects
When several drains stop working at once, the blockage sits in a pipe that several rooms share, so in the soil stack or in the main house drain.
There it is usually built up deposits, roots that have grown in, or a foreign object. Household remedies do not fix that, and it comes back unless the pipe wall itself is cleaned.
Common questions about blocked drains
How do I tell whether one drain or the whole pipe is affected?
Run water somewhere else in the building and watch the first drain. If it gurgles, the level rises or water comes up, both are on the same pipe and the blockage sits behind the junction.
Does hot water help?
With fresh kitchen fat, often yes. With hair, foreign objects and old hard deposits, no. Boiling water does not belong in plastic pipes or in a ceramic basin.
What about baking soda and vinegar?
The mix foams and loosens light films in the trap. It will not move a solid blockage. It usually does no harm to the pipe, so there is nothing against trying it before you reach for anything stronger.
I am renting. Who do I call?
If only your flat is affected, it is usually settled directly. If a shared pipe is involved, the property manager or the owner side should be informed. We are not allowed to give legal advice on this.
The drain runs again, but slowly. Is that good enough?
A drain that is permanently slow is a blockage in the making. The pipe is not closed yet, but it is already narrow. Waiting usually means the next standstill comes at the worst possible moment.