PLUMBING

Toilet Repair & Installation: Common Problems and When to Call a Plumber

From a constantly running toilet to a full replacement, here's how to diagnose common problems and know when it's worth calling in a plumber.

A toilet problem is one of those household issues that ranges from a minor annoyance to a genuine emergency, depending on exactly what's wrong. Here's how to tell the difference and what your options are.

Common toilet problems and what causes them

• Constantly running toilet — usually a worn flush valve or fill valve, wastes significant water if left unfixed.
• Weak or incomplete flush — often a partially blocked trap or a fill valve not delivering enough water.
• Toilet rocking or unstable — usually a failed wax seal or loose mounting bolts, which can lead to leaking at the base if ignored.
• Leaking at the base — often a failed seal, and worth fixing quickly since it can damage flooring underneath.
• Cistern not filling properly — typically a fill valve issue, straightforward to repair.

Repair vs replacement: how to decide

Most common issues (running toilet, weak flush, fill valve problems) are repairable without replacing the whole unit. Replacement makes more sense when the toilet is very old, cracked, or when you're already doing a broader bathroom renovation and want fixtures that match a new layout.

When it becomes an emergency

A toilet that won't stop overflowing, or one that's the only working toilet in the house, qualifies as an emergency call-out. Most other toilet issues can be scheduled rather than rushed — see our guide on what actually counts as a plumbing emergency.

Installation considerations

When installing a new toilet — whether replacing an old one or as part of a renovation — the seal between the toilet and the drain outlet is the detail that matters most. A poorly fitted seal is the single most common cause of new-installation leaks, so this isn't a step worth rushing or doing without the right materials.

Our approach

Toilet repair and installation is one of the most common plumbing call-outs we handle across Johannesburg South and Alberton — see our full plumbing services for everything else we cover.