Why does my toilet keep blocking?
Repeated blockage is a symptom — what goes down, a weak flush, or something wrong with the drain itself.
- Difficulty
- beginner
- Time
- 30 min
- Read
- 2 min
- Safety
- caution
Short answer
If it blocks regularly with normal use, either something unsuitable is going down it or the drain has a problem. Wipes are the usual answer; a weak flush and a partially blocked drain are the other two.
A one-off blockage is bad luck. A recurring one is a system telling you something, and the three possible causes need completely different responses.
Safety
Step by step
- Work out what is going down it.Wipes — including those labelled flushable — cotton buds, sanitary products, kitchen roll and dental floss all cause repeat blockages. Only paper and waste should go down a toilet.
- Put a bin in the bathroom.The practical fix for the most common cause. If everyone in the house has somewhere else to put things, they mostly will.
- Check the flush is strong enough.A weak flush does not carry waste far enough down the drain, so it accumulates. Check the cistern fills fully and the flush valve seals properly.
- Check the cistern water level.There is usually a marked fill line. If the level has dropped — a misadjusted float or a leaking valve — the flush is weaker than it should be.
- Try a full bucket of water instead of the flush.If a bucket clears it easily but the flush does not, the flush is the problem rather than the drain.
- Look at the drain outside.Lift the nearest inspection cover. Standing water means a blockage further down. Regular partial blockages usually show here.
- Consider the age and route of the drain.Old clay drains crack and shift, and tree roots find them. Repeated blockages in an older property with mature trees nearby are a common pattern.
- Get a camera survey if it persists.A drainage company can put a camera down and see the cause. It is not expensive, and it stops the cycle of clearing the same blockage repeatedly.
Tips
- Flushable wipes are the single largest cause of blockages in domestic and public sewers. They pass the toilet and do not break down.
- If the blockage is always in the same place, that location is the clue. Note it — a drainage engineer will ask.
- If you rent, report repeated blockages in writing. A recurring drain problem is usually the landlord's responsibility.
Questions people ask
Why does my toilet block so often?
Usually something unsuitable being flushed — wipes most commonly — or a weak flush, or a partial blockage in the drain itself. Each needs a different response.
Are flushable wipes safe to flush?
No. They pass through the toilet but do not disintegrate in the sewer, and they are the most common cause of repeated blockages.