Check other nearby fixtures
If only the shower is slow, the restriction may be local. If the basin, bath or floor waste is also affected, the problem can be further downstream.
Avoid repeated harsh chemical treatment
Chemical products may not remove solid obstructions and can complicate later work. The clearing method should suit the type and location of the blockage.
Recurrence matters
A drain that blocks again soon after clearing may justify inspection for poor fall, damaged pipework, roots, foreign objects or another underlying cause.
Related information
Blocked Drains
A blocked drain is a symptom. The useful question is whether the obstruction is local, recurring or caused by a defect in the drainage system.
Blocked Toilet: First Steps Before Calling a Plumber
Repeated flushing can turn a simple blockage into an overflow. The first objective is to stop adding water and establish whether the problem is limited to one toilet.
Drain Smells
Drain odours can come from a dry trap, fouling, defective seals, poor venting or a drainage problem further downstream.
When Is a Drain Camera Inspection Worthwhile?
Camera inspection is most useful when the question is why a blockage keeps returning or where a structural defect is located.