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How to install a toilet

How to install a toilet

Does your old toilet need replacing? If so, this guide could provide you with all the advice you need to fit a new one. Many aren’t aware that a toilet can be installed DIY, but with the following steps you could have your brand-new toilet up and running in no time.

Table of contents

  1. Reasons for a new toilet
  2. How a toilet works
  3. How long does it take to install a toilet?
  4. How to prepare for fitting a toilet
  5. How to remove the old toilet
  6. How to dispose of the old toilet
  7. How to install a new toilet
  8. Aftercare
  9. When to call a professional

Reasons for a new toilet

There are a number of reasons for installing a new toilet. It’s usually quite simple to spot signs that your current loo needs replacing. These include:

  • Frequent clogging
  • Frequent repairs
  • Cracking, scratches or rusting
  • General upgrade
  • Bathroom remodelling
  • To save water and energy

How a toilet works

In simple terms, a toilet is made up of a tank and a bowl. The tank (called the cistern) is positioned above the bowl and contains water that refills after each flush. The bowl holds water and links to the sewage drain for waste and water disposal. When the toilet is flushed, water from the cistern flows into the bowl forcing the contents through the ‘S bend’ and out to the sewage pipe.

how a toilet works

How long does it take to install a toilet?

It typically takes 1-4 hours to fit a toilet depending on the type of toilet you are fitting and your experience in conducting the job. Then you just need to fit your toilet seat, which should only take minutes (depending on the toilet!).

How to prepare for fitting a toilet

There are a few measures you’ll need to take prior to installing your new toilet. These include:

Ensuring you have the right equipment

Here are the main tools you’ll need for the job:

  • Screwdriver
  • Wrenches
  • Rubber gloves
  • Silicone
  • Adjustable pliers

If you’re installing a toilet from scratch or fitting a system that has a cistern tank that is not connected directly to the pan or bowl, you may need to use some of the following equipment too:

  • Hammer
  • Drill
  • Bucket
  • Pipe wrench
  • Tape measure
  • Box spanner
  • Spirit level
  • Pipe Cutter or Hacksaw
  • Pencil
  • Towel
  • Flexible hose

How to remove the old toilet

  • Turn off the water supply – You need to ensure that there is no water in the toilet’s cistern tank or bowl. Turn off your water supply using the isolation valve, then flush the toilet until no water is left. You may notice that there is some water that is leftover in the cistern or pan. To get rid of this, you can use an old towel to push it down, then wring the towel out over a bucket.
  • Disconnect the water pipe from the cistern – The water pipe that connects to your toilet system’s cistern filters water into it when required. Disconnect it using a wrench, be sure to lay a towel underneath the pipe in case any water leaks out.
  • Remove the fixtures – For this step, you’ll need to remove the elements that fix your toilet to the floor. Carefully unscrew the nuts and washers and remove any silicone to help release it.
  • Detach the soil pipe – There should be an outlet at the back of your toilet that connects to the soil or waste pipe. Very carefully, and gently, detach the toilet from this pipe.
  • Cover the soil pipe – Finally, using a bag or cloth, cover and seal the soil pipe to stop the potentially harmful and unpleasant gasses from entering the room.

These preparatory steps will also allow you to identify any elements that need replacing, other than the toilet.

How to dispose of the old toilet

We recommend taking your old toilet to your local household waste recycling centre (also known as “the tip”). You can find your local tip by searching online or visiting your local council’s website, you can also call them prior to making the trip to ensure that they can accept it.

Remember to ensure that the toilet is clean and dry before moving it and taking it to the recycling site.

How to install a new toilet

Now for the main event – installing your new toilet.

Note: We recommend reading through your manufacturer’s instructions before you begin.

Here’s our step by step guide to fitting your new toilet:

  1. Assemble and insert the flush mechanism. Include the rubber sealing rings and be careful not to over-tighten any of the fittings.
  2. Take the large rubber gasket and fit it into the flush entrance of the pan.
  3. Place the long fixing bolts into the holes in the cistern, make use of the metal washers supplied.
  4. Lift and place the cistern onto the toilet pan and ensure that the connecting bolts fit into the holes.
  5. Fit washers to the bolts and tighten using the wing nuts.
  6. Check for any cable or pipes beneath the fixing points before putting the toilet in place. Next, slide the pan outlet into the flexible connector that is attached to the soil pipe. You’ll then need to drill some pilot holes into the floor in line with the fixing points (being careful not to hit any pipes or cables!).
  7. Get plastic protective inserts and push them through the holes in the base of the pan, then put the retaining screws through and into the floor. Should the cistern have fixing holes in the back, you’ll need to attach it to the wall by drilling and plugging.
    Tip: Be sure to add rubber washers before you begin to tighten the nuts.
  8. For the cold water feed, you’ll need to connect the supply pipe using a push-fit tap connector.
  9. Using the instructions outlined in the manufacturer’s guide, fit the hinge assembly to the toilet seat.
  10. Using screws, connect the seat to the pan – you should secure this through the holes at the back. Finally, adjust it to the right position. Take a look at our helpful guide on how to fit a toilet seat, for more information.


Some say that toilets can last up to 50 years. However, there are a number of ways in which you can help prolong the life of your bathroom throne. These include:

  • Ensuring that it is maintained properly – This includes using non-abrasive cleaners to avoid damage and using brushes with plastic bristles instead of harsh wire ones. Take a look at our article on how to clean your toilet to find out more.
  • Use it properly – We’re sure you know how to do this! However, you shouldn’t lean back on the seat against the tank/cistern and never stand on the lid or seat – even if it’s to reach something!
  • Try not to drop the seat lid down too hard when closing the toilet.
  • Don’t treat your toilet like a bin – You shouldn’t use your toilet to get rid of any plastic waste, thick materials or even toiletries such as facial wipes, baby wipes or feminine hygiene products.
  • Deal with any issues with your toilet as soon as possible:
    You should get any issues rectified straight away to avoid any lasting damage. Our pages on How to fix a toilet that won’t flush and How to replace a toilet ball valve can help you solve DIY issues. Alternatively, our home repairs team are on hand to help with any plumbing and drainage issues you may have.

When to call a professional

A problem may arise with your toilet and if you’re not confident in being able to sort it yourself, we can help. HomeServe have a network of plumbing and drainage experts that could help. Get in touch with our home repairs team to find out more.

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