Plumbing advice
Slow-Draining Sink or Shower? What to Check First
Recognise a developing blockage, avoid making it worse and work out when to call a plumber or your wastewater company.
Water lingering in a sink or shower can be an early warning of a blockage. Avoid repeatedly filling it to see whether the problem has disappeared. Start by noting which fittings are affected and whether there are other warning signs.
Check the pattern
Is just one basin slow, or are the bath, sink and toilet all behaving differently? Have you noticed gurgling, unpleasant smells or water appearing elsewhere when a fitting is used? Record when the problem started and whether it is getting worse.
Thames Water lists slow drainage and difficult flushing among blockage symptoms. A problem affecting several properties, or wastewater escaping outside, may involve shared or public pipework. Contact your own wastewater company for advice rather than assuming every blockage is inside your home.
Keep checks simple and safe
If a removable strainer or surface drain cover is designed for routine cleaning, clear visible hair and debris according to the fitting’s instructions. Wear suitable gloves and put the waste in the bin. Stop if access requires dismantling unfamiliar fittings or opening an electrical shower unit.
A surface clean cannot establish what is happening farther along the pipe. If drainage remains slow, arrange an assessment. Tell the plumber about any drain-cleaning product already used, including the name and when it was added, before they begin work.
If wastewater starts rising, stop using affected fittings and appliances that discharge into them. Keep children and pets away from contaminated water. Do not lift heavy drain covers or enter any inspection chamber. Get urgent assistance if flooding is developing.
Reduce the chance of another blockage
Keep food scraps and cooking fat out of the sink. Use a suitable strainer to catch debris and empty it regularly. Southern Water recommends drain protectors for hair and food waste and explains why washing-up liquid does not make pouring fat away safe.
Only human waste and toilet paper should go down the toilet. Wipes, sanitary products and cotton wool belong in the bin, including wipes marketed as flushable.
For a recurring problem, ask the contractor how they will identify the cause and what the quoted clearance includes. You can find local plumbing businesses or browse blocked-drain services. Check whether they handle internal waste pipes, outside drains or both.