Knowing what is actually blocking your drain helps you decide whether to try a DIY fix, call a plumber straight away, or just live with it until it gets worse. Here is how to read the signs.
Slow draining in one fixture
If it is just one sink or shower that drains slowly, the blockage is local. Usually hair, soap scum, or grease has built up in the trap or just past it. A plunger followed by a kettle of boiling water clears most of these. If it does not clear, you might need a small hand auger from Bunnings.
Slow draining in multiple fixtures
If two or more fixtures drain slowly, the blockage is further down the system, in a shared section of pipe. This is usually a main drain issue and you need a plumber. DIY plungers and chemicals will not reach the problem.
Gurgling sounds
Gurgling from a sink or floor drain when another fixture runs (like the washing machine) usually means a partial blockage in the main line. Air is being sucked through the wrong drain because water flow is restricted. Get this looked at before it becomes a full blockage.
Sewage smell
Persistent sewage smell, especially in the bathroom or laundry, often means a blocked vent pipe or a problem with the main sewer line. Worth a CCTV inspection to find the cause rather than guessing.
Toilet not flushing properly
If water rises high in the toilet bowl and drains slowly, the blockage is in the toilet drain or the line shortly after. Plunger first, then consider a plumber if that does not clear it.
Backups out of floor drains
Water or sewage coming up out of a floor drain (especially in the laundry or shower) means a serious main line blockage. Stop using all water fixtures immediately and call a plumber. Continuing to run water will make the backup worse.
Recurring blockages in the same drain
If you keep clearing the same blockage every few months, the cause is usually tree roots in the sewer line or a collapsed section of pipe. A CCTV camera shows exactly what is happening. Spot repair or relining solves it permanently.
When to call
Single fixture, slow drain: try DIY first.
Multiple fixtures, slow drain: call a plumber.
Any backup, gurgling, or sewage smell: call a plumber promptly.
Recurring blockage: skip DIY and book a CCTV inspection.