1. Multiple fixtures are slow or blocked at the same time
If several fittings drain slowly together, the blockage is probably in a shared pipe, since they all use it. A plunger at one sink will not reach it. A CCTV drain survey can show what is wrong.
Do not wait, since the blockage can grow. A professional can clear it and check the pipe.
2. Sewage smell when no water is running
A smell with no water use points to a problem in the pipe or trap, because gas is escaping. It may be a crack or a dry trap. It may also be a sign of waste sitting in the pipe.
Check for dry traps first. If the smell stays, call an engineer. Read our guide on what to expect from a CCTV drain survey.
3. Gurgling sounds from other fixtures
Gurgling means air is moving through the drain, and it can happen when a pipe is partly blocked. It can happen when a pipe is partly blocked. Flush a toilet and listen to the sink.
If the sound repeats, the drain may need clearing. A blocked vent can cause the same noise, so ask an engineer to check.
4. Water rising in the inspection chamber
A full chamber shows that water cannot leave, so the blockage is further down. The blockage is probably further down the pipe. Keep the cover on and keep children away.
Stop using water in the house, since it adds to the problem. Call a drainage engineer, because this is a clear sign of a blocked drain.
5. The same drain blocks repeatedly
A drain that blocks again and again has a cause that cleaning does not fix, because debris keeps catching. It could be roots, a crack or a low spot. Debris collects at these faults.
A survey finds the cause. Our guide to pitch fibre pipes covers one possible cause in older homes.
6. Toilet water rises before draining
If the toilet bowl fills before it empties, the blockage may be close by or further down, so watch the other fittings. A plunger may help, but if the problem returns, call an engineer. Other fittings may be slow too.
Check for gurgling in the bath or sink. If you notice it, the main drain may be affected.
7. Slow drainage has worsened over months
A slow decline suggests a build-up of grease or roots, because it rarely fixes itself. It rarely fixes itself. The pipe narrows a little more each week.
Act while it is still draining. Early cleaning is simpler than clearing a full blockage.
8. You can see a crack or joint separation in visible pipework
A crack in a visible pipe may leak waste, since the wall no longer holds water. Joints that have moved can let water out and roots in. Look at pipes in cellars, garages and under floors.
Replace damaged sections. Ask a plumber to check how far the fault goes.
9. Damp patches on walls or ceilings near drains
Damp near a drain may point to a leak, so look for stains and a musty smell. Look for stains and a musty smell. Our guide to how to find a water leak explains how to trace it.
Do not ignore damp, because it grows. An engineer can check if the drain is the cause.
10. The drain is more than 30 years old and has never been surveyed
Older drains can hide faults, because nobody sees inside them. If nobody has looked inside, you do not know what is there. A survey gives you the facts.
You can request a free quote and we will pass your details on. A CCTV drain survey is a sound first step.
When to act
Act when you see any of these signs, since waiting often makes the job bigger. Waiting often makes the job bigger. Our drain cleaning and unblocking page explains how engineers clear blockages.
Take notes and photos of what you see. They help the engineer find the cause faster.
Related guides and local help
If you want to know more, read 7 Things You Should Never Flush Down a Toilet in the UK. You can also read Shower Not Draining: What You Need to Know to Fix It and Tree Roots in Drains: How They Get There and What to Do, because they cover closely related problems.
These guides help too: Sewer Smell in the House: Causes and How to Fix Each One, Blocked Drain Clearance Cost Guide: What Affects the Price, 10 Plumbing Myths That Cost UK Homeowners Serious Money, Chemical vs Mechanical Drain Unblocking: Which Works Best? and Outside Drain Blocked: What to Do and Who Is Responsible. Each one explains a related topic in plain English.
Need help near you? Read our blocked drain guide first, or see Blocked Drains in Swindon and Blocked Drains in Sunderland. You can also see Blocked Toilets in Borrowash, since every service page has a free quote form. We pass each request to a local drainage engineer.
