Blocked drain: unblock yourself or call?

Many minor blockages are in the trap or the first section of drain and can be resolved with simple means. If it's deeper down or several drains are backing up at once, that indicates a blockage in the main pipe — and then professional equipment is needed.

Step-by-step plan: how to tackle a blocked drain yourself

Always start with the mildest approach and only go a step further if it doesn't help. This prevents damage to pipes and rubber seals.

1. Check which drains are slow. Is it one, or are other drains in the house also draining poorly? If several drains at once, you can skip the steps below and better call straight away.
2. Stop using the drain for now. Don't run any more water and switch off the dishwasher or washing machine while the drain is slow.
3. Remove what you can see. Remove the grate or plug from the shower or washbasin and pull out hair and soap residue, for example with a hook or an old toothbrush.
4. Try warm water for a kitchen or basin drain. Use hot tap water, not boiling water, especially not with PVC pipes.
5. Use the plunger. For a washbasin or kitchen sink, cover the overflow with a wet cloth, otherwise the pressure will escape there. Push down firmly a few times, then pull it off in one go.
6. Clean the trap if it is still slow. Place a bucket underneath, unscrew the trap by hand, rinse it out and screw it back on. Then check that it is not leaking.
7. Try a hand snake if available via the drain or at the trap. Turn gently and don't force anything.
8. Not working after these steps? Then stop and call in a tradesman. Persisting often makes a blockage more solid.

The cause varies per drain

Kitchen. In the kitchen drain the problem is almost always grease, coffee grounds and food scraps. Grease solidifies in the pipe and catches everything that passes. With a kitchen sink, cleaning the trap often helps; see also unblocking a kitchen sink.

Shower and bath. Here, hair and soap are the main culprits. Together they form a tough plug just below the drain. If water comes up in the shower when you flush the toilet or the washing machine pumps, then it's further down the pipe. Read about this at water coming up in the shower.

Toilet. A toilet becomes blocked mainly by wipes and too much paper. In blocked toilet: DIY or call you can read how to use the plunger properly, and at what can go down the toilet what is better off in the bin.

An overview of all rooms in the house is at blockage per room.

What you'd better not do

• Using different drain cleaners one after another or mixed together. They can react with each other and produce dangerous fumes. More about this at drain cleaners: what works.
• Pouring boiling water into a PVC drain or toilet. PVC can deform and porcelain can crack.
• Poking hard objects into the drain, such as wire or a screwdriver. This damages the pipe or pushes the blockage further away.
• Keep flushing or leave the tap running while the water cannot drain away.
• Unscrewing a trap without a bucket underneath, or opening up a pipe that you can't seal properly again.

How to make the decision

A simple rule of thumb: if the problem is in one drain and you can see where it is, it makes sense to try yourself. If several drains are slow, water is coming up or you smell sewage, the problem is in the main pipe and there is little you can do yourself. Also, if a blockage keeps returning after a few weeks, it is time to call a tradesman. The cause is often a layer of grease, subsidence or a damaged pipe. A camera inspection reveals what is going on inside the pipe, so that targeted repairs can be made.