How to install plumbing for a toilet: a homeowner's guide

How to install plumbing for a toilet

Andrew Vanny Plumbing

How to install plumbing for a toilet: a homeowner’s guide

Installing a new toilet suite might seem hard, but you can do it yourself with the right tools and advice. This guide will help you through the process, whether you’re updating your bathroom or just replacing an old toilet. Upgrading to a modern, water-efficient model can save you money on your water bills1.

Key Takeaways

  • DIY toilet installation is achievable with the right tools, materials, and guidance
  • Assess your current toilet for signs of wear and tear, and consider upgrading to a water-efficient model
  • Measure the rough-in size accurately to ensure a proper fit of your new toilet
  • Gather all necessary tools and materials before starting the installation process
  • Follow the step-by-step instructions carefully, from removing the old toilet to installing and testing the new one
  • Address common issues such as wobbling and leaks for a successful, long-lasting installation

Assessing When to Replace Your Toilet

Knowing when to replace your toilet is key to a working and efficient bathroom. Toilets last a long time, but problems can happen, which means you need a new one. Spotting signs of a faulty toilet and knowing the perks of a water-efficient model help you decide what your bathroom needs.

Signs of a Faulty Toilet

Some signs show your toilet needs replacing. If it clogs often, even after using a plunger or auger, it might be the toilet’s fault2. Small cracks in the bowl or tank can cause big water damage if ignored2. A toilet that keeps running can mean internal issues and higher bills2. Studies show many toilets need replacing because of clogs and repairs3. Some toilets also have cracks and leaks, causing water damage.

Benefits of Upgrading to a Water-Efficient Model

Switching to a water-efficient toilet has many benefits. Old toilets waste a lot of water with each flush, but new ones can save thousands of litres a year. This saves water and lowers your bills. Old, inefficient toilets often raise water bills3. In Forster, many homeowners upgrade to efficient toilets during bathroom makeovers, improving looks and use. More homeowners want toilets with new designs and comfort features.

Choosing a reputable plumbing service is key when replacing a toilet. In Mandurah, many plumbing companies are well-regarded by customers3. The area has lots of licensed, insured, and skilled plumbers3. They offer good prices and keep customers happy.

Gathering the Necessary Tools and Materials

Before you start your DIY toilet replacement, make sure you have all the tools and supplies you need. It’s smart to make a detailed list to avoid going back to the store often. Plumbing and electrical work can be about 30% to 40% of a bathroom’s total cost.

Your toolkit should have a new toilet, extra wax ring, measuring tape, and more. Don’t forget a utility knife, pry bar, bucket, and sponge. You’ll also need water solidifier, putty knife, hacksaw, screwdriver, and an adjustable spanner.

For removing old pipes and parts, hacksaws are key. Plumber’s tape helps stop leaks and works well in different temperatures. Don’t forget gloves and an old rag for cleaning.

When picking a new toilet, check that it fits your space and leaves room for other items. Most homeowners look online for ideas and materials.

For a successful toilet replacement, consider a drain auger for clearing big lines5. Safety gear like goggles, gloves, and heat shields are also important.

Having all your tools ready will make your project go smoothly. Remember, 65% of homeowners focus on looks and function in their remodels4. Choose materials that fit your style and budget.

Measuring for Your New Toilet

When you’re planning to renovate your bathroom or replace an old toilet, getting the measurements right is key. With 4.2 billion people worldwide lacking proper toilets, many face the need for replacements6. Toilets usually need replacing every 10 to 15 years, so making sure you measure correctly is vital for a good fit.

Make sure your new toilet fits well by measuring the space where your old one was. The distance from the wall to the floor drain’s centre is what you need to measure. In Australia, most toilets have a 140mm rough-in size, but it can be up to 165mm or 180mm. Check your measurements carefully and pick a toilet that fits your bathroom’s size.

Determining the Rough-In Size

The rough-in measurement is how far the toilet is from the waste pipe. It’s important because the wrong measurement can affect which toilet you can install6. In Australia, most S-traps are 140mm7. If you measure this wrong, you might have to spend more money fixing it later, as the wrong toilet placement can increase costs by three times.

To find the rough-in size, measure from the wall to the drainpipe’s centre. This is key for fitting the toilet right7. But, things like old fixtures or uneven walls might hide the true measurement8. Getting this measurement right is crucial to avoid leaks or other problems later.

Ensuring Compatibility Between Cistern and Pan

If you’re just replacing the cistern or pan, make sure it fits with the old one. They must match for good flushing and saving water. Check the cistern’s height to fit under any space limits.

The pan’s height and size matter too, making sure there’s enough space around the toilet7. Toilet bowls come in different sizes and shapes. Round ones are better for kids or short people, while oval ones are for most adults. This means you need the right measurements for a good fit6. Different toilets need different spaces, so this must be considered in your planning.

By focusing on the right measurements and compatibility, your bathroom renovation will go smoothly. Professional plumbers stress the importance of precision and following standards for a successful toilet install. This ensures your toilet fits well and works perfectly8.

Removing the Old Toilet

Before you start replacing your old toilet, make sure to remove the old one correctly. On average, a homeowner can do this in a day. It’s key to follow the right steps for a smooth toilet removal.

Shutting Off the Water Supply

First, turn off the water supply. Most homes have a stopcock near the toilet for this9. In most cases, just turning the valve on the toilet’s supply line stops the water10. Find the shutoff valve at the toilet’s base and turn it clockwise to stop the water flow.

Disconnecting the Water Supply Line

After shutting off the water, flush the toilet to empty the cistern and bowl. Use a sponge or mop to remove any leftover water. About 85% of toilets need a wrench to disconnect the supply line10. Take off the water supply line from the cistern, and have a bucket ready for any water that comes out.

Unbolting and Lifting Away the Old Toilet

Before taking the toilet apart, drain the bowl of any water, which is needed for over 60% of toilets10. Take off the caps over the bolts at the toilet’s base, then unscrew the nuts. About 70% of toilets have bolts that are rusted or stuck, needing a hacksaw to cut them off10. Rock the toilet gently to break the seal with the floor and lift it up. Toilets usually weigh 50-60 pounds, so getting help is a good idea10. In about 40% of cases, you can unattach the tank from the bowl for easier removal10.

If you’re having trouble removing the toilet, don’t worry. Plumbers Direct offers installation and replacement services, showing the need for expert help with toilet plumbing. A 24-hour plumber hotline number (1300 896 508) is there for any issues during the installation.

Preparing the Area for the New Toilet

Now that the old toilet is gone, it’s time to get ready for the new one. First, take out the old wax ring. Then, check the flange for damage. Make sure the flange is level with the floor.

Removing the Old Wax Ring

Start by removing the old wax ring. This can be a bit messy. Use a putty knife to scrape off the wax from the closet flange ring. Throw it away right away because it’s dirty and sticky.

Make sure you clean the floor flange and around the drain hole too.

Checking the Flange for Damage

Next, look at the flange for any damage. It should be securely attached to the floor. If you see cracks or big damage, you should replace it.

A damaged flange can cause leaks and a bad seal. This can mess up your toilet installation.

Ensuring a Level Flange

Use a level to check if the flange is even. It should be about 1/4 inch to 3/8 inch above the floor for the right installation11. If the flange is not even, you might get leaks or a bad seal.

So, make sure it’s fixed before you start installing the toilet. Use shims to level it out if needed.

By removing the old wax ring, checking the flange, and making sure the flange is level, you’re setting up for a good toilet installation. These steps help stop leaks and make sure the toilet fits well.

Installing the New Toilet

Now that the old toilet is gone and the area is ready, it’s time to install the new one. This step is key. It includes putting the wax ring in place, making sure the toilet fits right, connecting the flush pipe, and attaching the water supply line. Doing this right means no leaks and a working toilet.

Positioning the New Wax Ring

Start by putting a new wax ring on the flange. Some people like wax-free silicone rings for a cleaner install and a good seal. Make sure the wax ring is right in the middle of the flange for the best fit with the toilet.

Remember, 67% of toilets leak because the seal isn’t done right.

Aligning and Securing the Toilet

Lower the toilet bowl over the flange carefully, using the closet bolts to line it up. Press down on the bowl to make the wax ring seal well. Then, put washers and nuts on the bolts, tightening them bit by bit to hold the toilet steady.

Don’t tighten the nuts too much, as it can break the porcelain. Make sure the toilet is straight using a level, which is key for it to work right and look good.

Connecting the Flush Pipe

Next, put the cistern on the pan, making sure it’s level and secure. Connect the flush pipe from the pan to the cistern, checking the seals are right and in place. A good connection stops leaks and makes sure it flushes well.

Reattaching the Water Supply Line

Finally, connect the water supply line to the cistern. Turn the water back on and let the cistern fill. Flush the toilet a few times to check it works and look for leaks. If you find leaks, adjust the nuts and seals as needed.

By following these steps and focusing on the right spots, you can install your new toilet well. Remember, it usually takes 4 to 6 hours to do it. But, it might take longer if you’re new at it or if you run into problems.

Completing the Installation

Now your new toilet is in place and hooked up to the water, it’s time to finish the job. This part is key. You’ll attach the toilet seat, check it works right, and maybe add caulk for a nice finish.

Attaching the Toilet Seat

Start by following the maker’s guide to put the toilet seat on. How you attach it can change with the model, but it usually means lining up the seat and using the given parts to secure it.

Testing for Proper Function and Leaks

After the cistern fills with water, check your work. Flush the toilet a few times to make sure it’s all good, watching the flushing and water flow. Look for leaks at the toilet base and where the water line meets the cistern. Fixing leaks quickly is key to stop water damage and make sure the install is a success.

Applying Caulk Around the Base (Optional)

Adding silicone caulk around the toilet base is a good idea for a clean look and to stop water from getting under it. But, wait a few days to use the toilet first to check for leaks or other problems.

When you’re sure your toilet works well and leaks are gone, put a thin caulk line around the toilet base. Use your finger or a tool to smooth it out for a neat finish. Let it dry as the maker says. Good caulking makes your toilet look better, keeps it in place, and protects your bathroom floor from water damage.

Troubleshooting Common Issues

After putting in your new toilet, you might face some common problems. These include a toilet that wobbles or leaks between the toilet and the floor. Fixing these issues quickly stops more damage and keeps your bathroom plumbing working well.

Addressing a Wobbling Toilet

If your new toilet wobbles, it might mean the floor is uneven or the bolts aren’t tight enough. Here’s how to fix it:

  1. Use a level to see if the floor under the toilet is even. If not, use shims to level it.
  2. Make sure the bolts that hold the toilet to the floor are tight but don’t overtighten them, as this can break the porcelain.
  3. After the toilet is level and the bolts are right, put caulk around the base. This makes it look neat and stops it from moving.

Preventing Leaks Between the Toilet and Floor

Leaks between the toilet and the floor can damage your bathroom and make it dirty. To stop this, make sure the wax ring is in the right place and seals well between the toilet and the drain. If leaks don’t stop, try these steps:

  • Check if the wax ring is in the right spot and covers the drain hole. If not, you might need a new or different wax ring.
  • Make sure the flange bolts are tight. If they’re loose, the toilet won’t seal properly with the wax ring.
  • If leaks keep happening, the flange might be the problem. It could be damaged or not installed right, so you might need to fix or replace it.

Any leaks mean there’s a problem that needs fixing quickly to stop water damage and keep your bathroom clean. If you’re not sure how to fix it, get help from a professional plumber.

Meeting Local Plumbing Codes and Water Efficiency Standards

When doing a DIY toilet install in Australia, knowing local plumbing codes and water standards is key. In Queensland, landlords must get a Water Efficiency Certificate to pass water costs to tenants21. The Queensland Plumbing and Wastewater Code, starting on 1 July 2019, sets the state’s plumbing and drainage rules22.

To meet water efficiency, rental toilets need a dual flush of 6.5 litres for full and 3.5 litres for half flush. Showers and taps must not flow more than 9 litres a minute2123. If a rental has its own meter, doesn’t go over the supplier’s bill, and meets water standards, landlords can pass on water costs.

The Queensland Plumbing and Wastewater Code requires meeting performance standards22. This can be done with deemed-to-satisfy solutions, performance solutions, or both22. The property must follow water efficiency rules at lease start to charge tenants for extra water.

For your toilet install to follow all rules, talk to a professional plumber. They can check your property, give advice on toilet installation rules, and help get a Water Efficiency Certificate. A licensed plumber ensures your renovation is up to code and saves water.

Installing water-saving devices is optional but necessary to pass water costs to tenants. Landlords pay for making properties efficient, but councils and water authorities offer rebates for it23. By focusing on water efficiency and following plumbing codes, you make a sustainable, compliant bathroom for everyone.


Our toilet installation guide has shown you the steps for a DIY plumbing job. It’s important to pay close attention and be ready for hard work. A small mistake could cause serious harm or damage your plumbing24. It’s smart to get help from professional plumbing services like us, Andrew Vanny Plumbing, even if you’re good at DIY. We work all over Sydney, and offer a wide range of services. We’re the plumber Kellyville trusts with toilet repairs and we’re the plumber Roseville calls for their bathroom repairs.

Experts can make the job easier for you. They ensure your bathroom renovation goes smoothly. They help pick the best toilet for your home and follow local rules. If problems come up, like clogs or broken water lines, they’re ready with the right tools and knowledge.

We hope our guide has given you the basics for a successful toilet project. You can do it yourself or get professional help. Remember, keeping an eye on water pressure and replacing old parts is important. This helps stop leaks and makes your toilet last longer. Congratulations on a job well done! Enjoy your new, efficient toilet for many years.


What are the signs that I need to replace my toilet?

Signs you need a new toilet include frequent clogs, porcelain cracks, leaks, and an old model that uses a lot of water.

What tools do I need to install a new toilet?

You’ll need a new toilet, wax ring, and some basic tools like a measuring tape and a utility knife. Other items include a pry bar, bucket, sponge, and water solidifier. Don’t forget a putty knife, hacksaw, screwdriver, and adjustable wrench. You’ll also need an old rag, garbage bag, plumber’s tape, silicone caulk, and gloves.

How do I measure for a new toilet?

Measure the distance from the wall to the centre of the floor drain for the rough-in size. In Australia, this is usually 140mm but can be up to 165mm or 180mm. Make sure your new toilet fits this size.

How do I remove the old toilet?

First, turn off the water supply and flush the toilet to drain it. Then, unscrew the water supply line and remove the bolts at the base. You might need a hacksaw for any rusted bolts. Finally, lift the toilet away.

What should I do with the old wax ring?

Use a putty knife to remove the old wax ring from the closet flange. Dispose of it right away because it can be dirty and sticky.

How do I install the new toilet?

Put a new wax ring on the flange and line up the toilet with the bolts. Press down hard and tighten the washers and nuts slowly. Then, attach the cistern, connect the flush pipe, and reattach the water supply line.

What should I do after installing the new toilet?

Put the toilet seat back on, flush it a few times to check everything works, and look for leaks. You can also use silicone caulk around the base for a clean look and to stop water from getting under the toilet.

How can I fix a wobbling toilet?

Use shims to level the toilet and make sure the bolts are tight but not too tight. This can crack the porcelain. Also, make sure the wax ring is in place for a good seal.

What should I keep in mind when installing a toilet in Australia?

Remember to follow local plumbing codes and water efficiency standards. If you’re having trouble or prefer a professional touch, consider hiring a licensed plumber. This ensures your toilet is installed right.


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