How to Replace a Toilet Cistern in 6 Easy Steps

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The humble toilet cistern is a key component of any toilet. It’s job is sending water from the tank it into the toilet bowl every time you flush. If your cistern stops working, it may have become cracked or damaged and will need to be removed and replaced in order to get your toilet working properly again. This can lead to water leaks requiring urgent attention.

You should first diagnose the problem before replacing your cistern, as sometimes repairs are possible or there’s another plumbing problem altogether. Is the issue that..

The answers to these questions will help you narrow down the cause and decide whether to DIY or call in a local plumber near you.

What DIY toilet plumbing am I allowed to do?

Most people understand that when you need electrical, gas or plumbing work done around the house, you’ll definitely need the best tradespeople you can find to do it for you. It’s not only illegal to get into certain types of serious DIY, but it can also be dangerous and can void your insurance – and if you get busted, you’ll have to shell out to have it all re-done anyway. But what about replacing a toilet cistern? Is a confident handyman able to get stuck into toilet plumbing repairs?

It depends what state you’re in (here’s a DIY plumbing guide you can check), but generally, you are permitted to fiddle with garden irrigation systems, repair leaking taps, replace showerheads or take basic steps to unblock a drain, and – YES! – replace things like your cistern’s drop valve and float valve washers and suction cup rubbers.

How to replace a toilet cistern

So we think it’s definitely worth our while to talk you through installing a replacement toilet cistern.

Firstly, if you’re not even aware that the toilet cistern is not the part you sit on, but rather the part behind your back that holds the flush internals and all the water, learning how to replace a toilet cistern is not for you.

But if you think you can replace toilet cistern components like a boss, grab your reliable plumbing tools and have a good look at Best Plumbers’ quick step-by-step guide below and good luck!

1. Flush the toilet

Firstly, you don’t want to turn a relatively simple job into a giant slushy mess, so make sure you give the toilet a flush to empty the cistern. Before you do that, turn off the stop tap (at the side of the toilet) and then head out to turn off the mains supply to be extra sure replacing a toilet cistern will not become Noah’s Flood!

2. Remove the cistern

Next up, grab a wrench and undo the inlet pipe at the bottom of the unit. You’ll then need to separate the cistern from the back of the toilet – it’s likely to be nothing more than a few nuts and bolts.

3. Check the new cistern

It’s always highly advisable to read through any instructions that came with your new cistern and double-check that you’ve bought the right one before getting wrist-deep in the job.

4. Install the replacement toilet cistern

Basically, replacing a toilet cistern is like removing a toilet cistern – in reverse! Hopefully, everything lines upright, especially the cone gasket at the bottom with the attachment hole at the back of the actual toilet.

5. Use your plumber’s tape

It’s important to use plumber’s tape on the inlet before re-attaching the hose to the replacement cistern, and then it’s just a matter of grabbing all of those nuts and bolts and doing it all up again.

6. Turn the water back on

You’re ready to turn the water back on, starting with the mains and then the stop tap. The new cistern should re-fill with water at this point, but be very watchful for any leaks. If it’s all good, give yourself a pat on the back – and celebrate by reading a chapter of your book on your favourite seat!

Was replacing a toilet cistern a little too tricky? Fear not – all the Best Plumbers are right here and more than happy to help. Finding the right plumber is easy with Best Plumbers, a unique and powerful plumbing network that instantly connects you with the very best plumbers in your local area.

Penrith plumbers, Gold Coast plumbers, Melbourne plumbers, Newcastle plumbers – no matter where you are Best Plumbers Club has you covered!