Replacing a toilet seems like a simple purchase, but getting it wrong turns a straightforward job into a complicated one. Before you buy a new suite, there are four things to get right — dimensions, plumbing configuration, water efficiency and installation.
1. Dimensions and set-out
The most critical measurement is the set-out — the distance from the wall to the centre of the waste outlet in the floor (for an S-trap) or the wall (for a P-trap). If the new toilet's set-out doesn't match the existing waste connection, the installation becomes more complex and may require altering the pipework.
Also consider the overall width and projection from the wall. In a small bathroom or powder room, a compact or wall-faced suite may be necessary. Measure the available space and compare it to the new toilet's dimensions before buying.
2. Plumbing configuration
The plumbing configuration determines what type of toilet you need:
- S-trap — connects to a waste pipe in the floor. Most common in Australian homes.
- P-trap — connects to a waste pipe through the wall. Common in wall-faced and modern suites.
- Water supply — check whether the inlet is on the left or right, and whether it's a top or bottom entry. A mismatch can require relocating the water supply.
You can't simply choose whichever trap type you prefer — your existing plumbing dictates it. If you want to change the configuration, the pipework needs altering, which adds cost.
3. Water efficiency (WELS rating)
Toilets carry a WELS (Water Efficiency Labelling and Standards) rating. A dual-flush toilet with a 4-star WELS rating uses around 4.5 litres for a full flush and 3 litres for a half flush, compared to up to 11 litres for an older single-flush model. For a family, the water savings are significant over a year.
A higher WELS rating also adds value when you sell, as buyers increasingly look for water-efficient fixtures. See our guide on common toilet installation questions for more on WELS ratings.
4. Installation quality and the seal
Even the best toilet will leak if installed poorly. The seal between the pan and the waste pipe (the pan collar or rubber cone seal) must be replaced, not reused, when fitting a new toilet. An old or compressed seal is a common cause of leaks and sewer gas odours after a replacement.
Toilet installation must be carried out by a licensed plumber in Queensland, as it connects to both the water supply and the sewer. Professional installation ensures the work complies, the seal is correct, and the warranty is protected.
Choosing a quality suite
Beyond these four considerations, choose a quality suite from a reputable brand. Cheap suites may have thin glaze that stains easily, plastic cistern components that fail early, and trap designs that block more readily. A mid-range suite from a known brand is usually better long-term value than the cheapest option.
If you're replacing a toilet on the Gold Coast, contact our team to confirm the set-out, recommend a suitable suite, and arrange professional installation.
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