The venerable flushing toilet. A miracle of engineering, a marvel that revolutionized sanitation and improved health of most living in developed areas. Yet, it is one of the things we least think about, that is, until it breaks.
In a departure from the norm, although, still strictly within the realm of what a practical engineer-minded person might take on, this post concerns itself with a troublesome toilet cistern.
Before we go any further though – if you don’t want to see anything gruesome and dirty, look away now. Don’t read any more of this post, call a plumber and fork over the cash.
The Patient, and the Diagnosis
The toilet in question is a Caroma dual-flush slimline at the one at the house I live in, a frequently used one. When it started to develop a leak into the pan, it was bad news. I knew it had to be fixed eventually, or it will eventually, spiral into a headache of water-waste and expensive water bills. But what is the issue? *Pops open the lid*
A leak into the bowl can be one of two things. At first, I suspected a leaking outlet valve, mounted at the bottom of the button assembly, and it may have been a contributor initially. It is a small piece of rubber that seals around the bottom of the cistern, which holds the water in the cistern until it is flushed. That is normally nothing major, and was replaced with the help of a family friend. The problem didn’t stop though.
A closer examination showed that it wasn’t the outlet valve – it was sealing just fine. The problem resides in the inlet float valve – the grey unit on the right. We can tell this because the toilet was filling past the water level mark, and hence overflowing.
As it was a newer design of toilet, it didn’t have an external overflow drain as some do. This is very convenient as it means you don’t get a flooded bathroom in case of the valve not closing properly – instead, it drains through the centre pipe into the pan. Aha!
The initial step was to see if this was a problem with the water level setting. I twisted the nylon adjustment screw on the float arm to actuate the valve earlier and get a lower water level.
This did try to stop the valve earlier, but the valve was still quietly hissing away and slowly admitting more water until it eventually overtopped the overflow. It did save a little water by setting it more conservatively, as nobody was prepared to deal with it at this stage.
Eventually, the leak got worse to the point I couldn’t stand to watch it keep going, and I decided I was going to fix it myself (or at least, try).
Repair or Replace?
A very good question is whether I should just repair the existing valve by replacing the membrane inside, or replace the whole unit altogether. The inlet valve on the Caroma dual-flush toilets aren’t particularly notable as of being high quality. In particular, they are known to develop leaks around the top cap, and there is a shortage of information of correct replacement of washers. Some horror stories include repaired valves leaking jets of water into the ceiling, flooding bathrooms, etc. That was something I didn’t need. They are also slow, noisy and hissy.
I suppose the biggest sway in the decision came when I went to Bunnings’ website and found a Fluidmaster Bottom Entry Toilet Inlet Valve listed for AU$19.50. This is pretty much a universal replacement fit for most bottom entry toilets, and the price was hardly objectionable when the cost of a replacement washer is about AU$4.79 and comes with a risk. Another option is the Fix-a-Loo Hush Flush Bottom Entry Cistern Inlet Ball Valve at the same price. These units would replace the whole grey inlet valve stem and should improve the performance over the existing valve.
One complication with replacing the inlet stem is that the length of the stem’s bushings might be subtly different to that of the old valve, and if you have a solid pipe leading to the inlet valve, then you might find it doesn’t fit properly. If you want to save yourself the hassles of trying to work with pipe, then the easy way out is a quick-fit water connector. I did some measuring and realized I needed about 420mm of length, so the next closest was a Kinetic 450mm Flexible Water Connector for AU$4.30, on special. It’s a cheap form of insurance and labour saving.
A quick think reveals that there really aren’t many tools required for this job, but it’s always good to be prepared. This might include:
- An assistant, if you’re lucky enough to have one, who should aim to keep their hands clean.
- A large wrench to undo the nuts on the connecting pipe and the nuts holding the existing valve in place. Most critical.
- A flathead screwdriver to undo the locking pin and disconnect the float arm from the old valve for convenience. You could do without this, if you wish.
- A bucket, and disposable towel to mop up any water spills.
- A pipe cutter, in case you need to shorten your pipe, but this is only required if you’re not replacing your inlet pipe with a quick fit connector.
- Access to the outdoors and a hose for hosing down the mess you are going to discover.
- A lot of wipes, cloths, paper towel and gloves to clean any mess you find hiding in the toilet.
Undergoing the Operation
Warning: You will see some pretty dirty images which might make you sick, or make your stomach churn. Do take some comfort in the fact you can’t smell what’s happening. This is your final warning to avert your eyes, or at least, maybe not look at it while eating.
Disclaimer: As usual, I will not be held responsible for what may happen to you as a result of following, or attempting to follow, these instructions – including any damage, loss or injury that may arise directly or consequentially. Use your own brain, and think of what you are doing.
The first step to beginning the operation is to turn off the water to the cistern by rotating the stopcock fully clockwise.
Then, to avoid mess, you need to drain the cistern as completely as possible by doing a full flush and holding the button beyond where the valve automatically re-seats itself. So far, so good.
Because this toilet has a fully covered design for aesthetic reasons, to get access to the bottom of the cistern requires removing the toilet seat. I highly recommend gloves for this operation, since a lot of dirt tends to linger in the areas you can’t reach in normal cleaning.
To remove the seat, you need to undo the two plastic wing-nuts while keeping a hold on the screw itself, as it will have a tendency to spin around. Of course, give these a good wash while you’re at it, because you really don’t want dirtyness when you come to fit it back together.
Carefully lift the seat forwards while ensuring the plastic screw doesn’t get lost. This should liberate the seat assembly. I recommend running outside with the seat, as it will have a lot of grime on the mounting point, and hosing it down to clean it up.
Hold your noses, because you will discover years of grime that results from liquid that has gotten through the seat, mixed with cleaning products, and possibly semi-congealed into a mess on the porcelain too.
Yes, you’ll have to clean this too, if you want to continue with the repair, otherwise you risk contaminating other parts and getting your face at it when you’re on your knees with a wrench, undoing the inlet valve.
The reason for all of this is because we need to slide down the decorative cover that “covers” the flush-pipe connection so we have access to the bottom of the cistern. Much better!
Now, it’s probably a nice time to take out the brass pin from the existing float valve, by lifting it up, and pulling it out, so you can remove the float arm to make the process of uninstalling the old valve easier.
Unfortunately, from here-on, it involves strange angles and a bit of work with my “assistant”, so I didn’t grab many more pictures of the installation, but the first thing is to undo the metal water-supply nut from this side and let it slide down the pipe. Then, while holding onto the valve from inside, you can rotate and undo the plastic nut from the outside completely, which allows the whole unit to be removed.
If you’re opting to use the quick-fit connector, you will also remove the nut from the stopcock side and remove the pipe altogether. In its place, you will hand-tighten one end of the quick fit connector on the stopcock end at just above finger-tightness in preparation for connection to the new valve.
It is at this point, you unpack the new valve, read the instructions and set it up. Start by adjusting the total length so that the critical water level mark is 25mm above the overflow level of the cistern. This is done by rotating the top half of the unit while holding the bottom part through several “click” detents until it reaches the desired length. Fit the included washer to the bottom of the valve, flat surface facing the flat surface of the valve, and install the water debris filter if necessary (not normally).
Now, we need to “fit” the valve into the cistern. The plastic outside nut should be threaded over the pipe, ready to “hold” onto the valve from the underside of the cistern. Rotate it, so it fits without any obstruction to the float’s movement or interference with the flush valve. The bottom of the new valve is about the same length as the old valve, so presumably we can continue to use the existing pipe.
Actually, hold on a sec. The design of this valve is different to the Caroma valve, and after fitting, we discovered it would not fill at all. This was because the pipe was protruding past the olive (a sealing silicone bead-shaped ring around the pipe, not pictured, also known as a ferrule) about 20mm.
This valve requires the protrusion of the pipe past the olive of no more than 9mm. As a result, the existing pipe was completely removed by undoing the bottom nut at the stopcock. We used a pipe cutter to shorten the excess length to roughly 9mm and that was sufficient to ensure it was fitted correctly. The pipe was then re-fitted to the stopcock.
Alternatively, you can just replace the pipe with a quick-fit as there is no such pipe intrusion to the bottom of the valve to worry about.
The pipe needs to be “tucked into” the valve stem itself with the olive pushed up against the valve so as to make it seal. If you are using the quick-fit, you don’t need to worry. Once the fit looks right, the plastic nut that holds the new valve in place has to be done up to finger tightness, and possibly just a little more just to ensure a water-tight seal. Do not overtighten, or you will destroy the nut or crack the cistern.
Then, the water pipe nut has to be done up to the new valve, again, just a little above finger tightness to ensure a waterproof seal. None of these connectors need, or should be used with PTFE plumbers tape – they should seal nicely.
If you’re following the instructions supplied by the manufacturer, you are requested to flush water through the valve to purge rust and other debris – but this isn’t strictly necessary if you’ve already removed the pipe completely as it should be clean.
All that’s necessary is to turn on the water slowly, and watch it as it starts to fill. Are there any leaks? No? Good. If there are, shut off immediately, and fix them!
If the valve doesn’t fill, you’ve probably hit an issue with the flow restrictor and excess piping going into the valve itself, or you might have inadvertently turned off the mains. Maybe try the quick-fit hose and the valve outside of the cistern to be sure the valve functions correctly.
Once it approaches a fill, then it’s time to adjust the water level. As it happened, fresh out of the install, the water level was pretty close – and just a little bit over the mark.
On this Fluidmaster 400UK, the adjustment is easily done by turning a plastic screw to adjust the float level when it pushes against the valve. Nice and compact, looking good!
Et Voila! The water level is just below the water level mark when it is full, just the way it should be. The new valve itself is quiet and much faster than the old one, and closes with a definite stop rather than a protracted “hissing” like the old one. In all, a great choice, and I’m sure the alternative Fix-a-Loo would be pretty similar as well.
The final steps are to reassemble the flush pipe fascia, and then re-install the seat and cover on the cistern, which are simply the reverse of dismantling them. Job done!
I got sick of the leaking toilet, and I wanted it fixed. As a practical person, what better way to do it than do-it-yourself. In the process, I cleaned the toilet (yuck!), and didn’t need to consult a plumber. It will save water, which is good for the environment, and save on water bills.
Surprisingly, the whole inlet valve replacement isn’t expensive at all, and the new valve seems to be superior to the old. While it might have been possible to save even more money by replacing the washer itself, I didn’t want to risk other failures – the cistern’s been around for many years, and horror stories did abound. The whole valve assembly could be had for about the cost of four washers. I suppose you can say, I took the easy way out, but it still solves the problem and it does it well. It fills quicker, and it’s quieter.
Two weeks later, the replaced valve is working very nicely. However, it just became apparent that a second, lesser-used toilet in the house of the same model has a busted inlet valve which has been slowly trickling into the pan as it overflows.
Because I also bought the Fix-a-loo product, I decided to fit it into that toilet. The procedure is basically the same (except the valve needs to be 30mm above the overflow line, rather than 25mm), and the fix was accomplished without much hassle. Both of the valves do fit in the same cistern, but so far, my preference seems to be towards the Fluidmaster because it stops quicker and more positively when the float rises, with less of a hiss-period than the Fix-a-loo and it’s a little more compact, but that’s nitpicking. The Fix-a-loo doesn’t have a flow restrictor, so longer pipes may not be an issue in terms of sticking into the end of the valve, and it does have a superior 7-year warranty.
Goodbye inferior Caroma “stock” valves. I did try to open this one by twisting the top but it wouldn’t budge … oh well. I don’t look forward to seeing goopy disintegrating rubber … so it will just be disposed as rubbish.