Quick Introduction on How Toilets Work

This is a quick introduction on toilet cisterns, how they work and how we fix them.

So this is typical Australian or New Zealand toilet, called a closed coupled suite. We've got a system here sitting on top of a pan, the cistern's full of water, when you press the button on top either half or all of the water will dump down straight into the pan and flush whatever is in there away.

The way that this process works is that we have two valves. We have an inlet valve and a flush valve. So there's a tap down below, and when the tap's turned on, the water will flow in through the inlet valve and the water level will rise in the system until it reaches a set level and it will stop. Then when you press the button, the flush valve opens and allows that water to flush down.

So what can go wrong with a toilet system?

Well, firstly, with the inlet valve.  What will happen is that the inlet valve will start to malfunction, it will leak slowly and the level won't cut off, it'll continue to rise very slowly. Fortunately, it won't come out the lid of the system. There's an overflow pipe in the flush valve. It will start to flow over there, will flow down into your pan and trickle down that and run away down through the toilet. 

Unfortunately with the cost of water these days, if you're on a meter or if you're on tank water, that can be a phenomenal amount of money because that water is running 24x7. So that really needs to be fixed up in a hurry.

The other thing that can happen is with a flush valve.  The flush valve will start to leak and the same thing, the water leaks down into the pan and away, and it'll cost you a lot of money.

If it's the inlet valve is leaking, you won't hear any noise. So you will only find out by possibly put some food colouring into your system, and you'll see the colour leaking down and out of the toilet.  Alternatively, you could put some tissue paper around the bowl and then you'll see the water leaking out. 

If the flush valve starts to leak then as it leaks the level of the system starts to drop and then after a while, the inlet valve will kick back in and the water will come back up again. So you'll periodically, you'll hear the inlet valve open and you'll hear that the characteristic hiss of your toilet filling up, especially in the nighttime you'll hear that when there's not much noise around.  If you hear that then the signs are that it's a leaky flush valve.  Toiletspares.com.au has all the toilet cistern spare parts to fix the toilet.  In Australia this work has to be done by a licensed plumber, in New Zealand it doesn't. 


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