How to Install a Toilet: Easy DIY Guide

Installing a toilet yourself may seem complicated. But the thing is, with the right tools and some patience, it’s entirely possible to do a proper toilet installation without calling a plumber in Sydney. This blog will walk you through every step, from preparation and removing your old toilet to fitting your new one.

Before You Begin: What You Need for Toilet Installation

A smooth installation comes down to having the right tools, accurate measurements, and a clear understanding of how the toilet plumbing connects to both the waste pipe and the water supply. When everything is ready before you begin, the process becomes much easier.

Tools and Materials You Need

• New toilet that suits your available space and is compatible with your existing plumbing system.
• Wax ring to create a watertight seal between the toilet outlet and the floor flange connected to the drain pipe.
• Toilet bolts for securing the toilet firmly to the floor flange
• Adjustable wrench for tightening nuts on the toilet bolts and water supply line
• Utility knife for removing old caulk or trimming sealant
• Level to ensure the toilet is installed evenly
• Tape measure to confirm the correct measurements and rough-in distance
• Sponge and cleaning rags for removing leftover water and cleaning the area
• Alcohol wipes for cleaning and preparing surfaces before installation
• Pipe wrench for loosening tight or old plumbing connections
• Silicone sealant for sealing around the toilet base and giving a neat finish

Step 1: Shut Off the Water Supply

Before touching any part of the toilet, the water supply needs to be turned off. The shut-off valve is located on the wall behind the toilet or near the base of the toilet along the water supply line. Turn it clockwise until the water stops flowing completely, then flush the toilet to empty the cistern and bowl.

Step 2: Remove the Old Toilet

If you’re replacing an existing toilet, the next stage is removing it safely. Start by locating the bolts at the base of the toilet that secure it to the floor. Use an adjustable wrench to carefully loosen and remove them.

Once the bolts are removed, gently rock the toilet from side to side to break the seal underneath. The wax seal can be quite firm, so take your time and avoid using too much force. When the seal loosens, lift the toilet straight up and move it out of the way.

After removal, clean the surrounding area thoroughly. Wipe down the flange and floor with alcohol wipes so the new toilet has a clean surface to sit on.

If the toilet feels stuck, it could be sealed tightly with old wax or silicone. Gently lifting it with controlled pressure can help break the seal, but avoid damaging the floor or nearby plumbing.

Step 3: Inspect the Toilet Flange

The flange is one of the most important parts of toilet plumbing. It connects the toilet to the drain pipe and helps support the toilet while allowing a proper seal to be made to prevent leaks and odours. Before installing the new toilet, inspect the flange carefully.

Look for cracks, corrosion, or movement. A damaged flange should be replaced before continuing, because installing a toilet on a faulty flange often leads to leaks later on. The flange should sit level with the floor and be securely fixed in place.

Another important measurement to check is the rough-in distance, which is the space from the wall to the centre of the flange. In many Australian homes, this measurement is commonly around 130-180 mm, depending on the toilet design, so it’s always best to measure your setup to ensure the toilet fits correctly.

Step 4: Install the Wax Ring 

With the flange checked and cleaned, it’s time to create the seal that prevents leaks. Place a new wax ring or wax-free seal onto the flange so it sits centred and stable.

This seal plays a major role in toilet installation because it prevents wastewater and sewer gases from escaping beneath the toilet. A properly placed seal helps the toilet function correctly and keeps your bathroom hygienic.

Make sure the ring sits evenly over the opening of the flange. If it is slightly off centre, the toilet will not seal properly once it is installed.

Step 5: Position the Toilet

Now comes one of the most important parts of the process. Carefully position the new toilet over the flange and seal, aligning the holes at the base of the pan with the toilet bolts.

Lower the toilet slowly and evenly so it rests on the seal. Once it’s in place, apply gentle pressure by sitting or pressing down on the pan. This helps compress the wax ring and creates a tight connection.

Make sure to check the alignment. A well-positioned toilet will sit straight and balanced without rocking.

Use a level across the bowl to confirm the toilet is sitting evenly. Small adjustments at this stage can prevent problems later.

Step 6: Secure the Toilet to the Floor

Place washers and nuts onto the toilet bolts and tighten them gradually, alternating from one side to the other so the pressure stays even.

Avoid tightening using excessive force, because porcelain can crack if the bolts are overtightened. The goal is to hold the toilet firmly in place while keeping it level and stable.

If the toilet feels slightly uneven, small shims can be placed underneath the base to stabilise it before fully tightening the bolts.

Step 7: Connect the Water Supply

Once the toilet is secured, reconnect the water supply line to the inlet of the cistern’s fill valve underneath the tank. 

Attach the hose carefully and tighten it with an adjustable wrench until it is snug, but be careful not to overtighten. Before turning the water back on, check each connection to make sure it is properly fitted.

Step 8: Test the Toilet

After everything is connected, slowly turn the water supply back on. Allow the cistern to fill completely, then flush the toilet several times to confirm that the installation is done correctly.

While testing, look closely around the base of the toilet, the water supply line, and the cistern connections. Even a small leak is an indication that something needs tightening or adjusting.

Step 9: Apply a Silicone Sealant

Once you’re confident everything is working properly, you can finish by applying silicone sealant around the base of the pan. This creates a neat appearance and helps prevent water from getting underneath the toilet.

Apply a thin, even bead of silicone and smooth it gently for a clean finish. The sealant also adds stability and helps protect the floor around the toilet.

Allow the silicone to cure fully before heavy use so the seal remains strong and durable.

Toilet Installation Mistakes to Avoid

Being aware of the most common mistakes can help you avoid leaks, poor alignment, and expensive toilet repairs in Sydney later on.

• Mismeasuring the rough-in: Always double-check your measurements before buying and installing a new toilet to make sure it fits the available space and aligns properly with the existing plumbing.
• Incorrect wax ring placement: If the wax ring is not positioned or compressed correctly, it can cause leaks around the base and eventually lead to water damage.
• Overtightening the bolts: Tightening the bolts too much can crack the toilet’s porcelain, which will require a full replacement rather than a simple fix.
• Ignoring the flange condition: A damaged, loose, or uneven flange can affect the stability of the toilet and increase the risk of leaks over time.
• Forgetting to check for leaks: After installation, always flush the toilet several times and inspect the base and water supply connections to confirm everything is sealed properly.

Conclusion

Installing a toilet yourself can be a great way to save money and feel more confident tackling a home improvement project. By following the steps carefully and avoiding common mistakes, you can complete the installation properly and ensure your toilet is fitted securely. 

Take the time to measure accurately, check all connections, and test for leaks so everything works as it should.

However, if you prefer the job done by a professional, our team has the tools and experience to make sure your toilet is installed correctly and running at its best from the start.

You can call Hero Plumbing on 02 9137 8549 or submit a request through our online form. We’re here to help with toilet installation, repairs, and any other plumbing issues you may have.