Guide to Toilet Replacement

We’ve created a comprehensive guide to choosing a new toilet.


Whether your toilet is leaking, discoloured, cracked, wasting water, constantly running, ugly or you’re just looking to upgrade, this guide should help you when shopping for a new loo.

What To Consider When Choosing A New Toilet

What style of toilet do you have now?

What style of toilet do you want installed?

Do you have a back or bottom entry cistern?

Do you have a p-trap or an s-trap?

How much water is your toilet using per flush?

Plastic or Ceramic?

Every Toilet Has Two Main Sections


There are two main parts to every toilet – the cistern (or water tank) and the pan (the bowl that you sit on). The cistern holds enough water so that when you release the water, it will flush away what is inside the pan. Whilst most toilets work the same way, the connection between these two main parts varies in style.

Where does the water come in?

 Bottom Inlets and Back Inlets

There are two types of water inlets – from the bottom of the cistern, called a bottom inlet or from behind the cistern, called a back inlet.


Back inlets allow you to conceal the pipe where water enters your toilet, they look great but make it harder to swap or replace your cistern without moving the pipe behind the wall also.


Bottom inlets allow for an easier swap/replacement with minimal pipe moving and more available options.

Where does the water go out?

P Traps and S Traps


There are two possible ways water and waste can exit your toilet. Through a pipe in the wall (this is called a P-Trap toilet) or through a pipe into the floor (this is called an S-Trap toilet). When choosing a new toilet, it’s crucial you get this right so the new toilet can connect to the existing drainage.

ABOVE: Left: P Trap outlet. Right: S Trap outlet

WELS Ratings

Check the WELS rating when selecting a new toilet. Older toilets can flush up to 13 litres per flush! You can cut this down to 3 litres with a water efficient toilet. The higher the rating, the more water efficient it is.

Toilet Styles


With this style, the cistern is concealed behind a wall and the pan is in front of the wall. In wall cisterns are a popular choice in modern homes.


Due to the cistern being concealed, maintenance can be difficult and time consuming and it’s crucial enough space is allowed when installing for access. Keep in mind, the internal parts for these toilets can be hard to find, more expensive than standard parts and require ordering in to replace. We once had to order parts from Italy.


When the cistern and the pan are bolted together and both are in front of wall. Water flows from the cistern directly into pan without an extra pipe.


When the pan goes completely back to the wall. Very popular option, looks great and can make a tired bathroom look new again. Here is a picture that one of our inner west plumbers installed a few weeks ago that turned out great!


When the cistern and the pan are separate and they are joined by a pipe that is sometimes covered (see picture below) and sometimes not (see picture above). Link suites generally aren’t the prettiest option, but ceramic options and linking pieces can improve their appearance.

Ceramic or Plastic?

A simple and cost effective way to uplift the look of an old toilet is to upgrade any plastics to ceramic finishes. Plastic cisterns and seats can discolour over time and can make your bathroom look older than it is. These can be replaced by close coupled pans and back to wall close coupled pans but for a more cost effective option, consider just changing the cistern and the seat!

Other Things To Note

Cement or Silicone?

Toilets can be attached and sealed to the floor in a number of ways, silicone and cement are the most common. If your existing toilet is attached to the floor using cement,  removing the toilet can cause damage to the surrounding tiles.


Check The Footprint / Size

Not all toilets are the same size. When replacing an old toilet with new, the shape of the pan or cistern may be different. When the new one is installed, there may be visible outlines of the old – especially if the old toilet was cemented in, painted or tiled around.


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