Special dye to detect toilet leak?

[rosharch]

Hi all,

I bought some food dye to perform the toilet cistern test to see if water is leaking into the bowl but I've come across a handful of articles like this https://www.kingscotechemicals.com/diy-dye-leak-test-for-toilets/#:~:text=Dye%20leak%20tests%20for%2....

That basically say either the test doesn't work or special dye is required. I've searched Bunnings for this dye online and come up with nothing.

Anyone more knowledgeable able to advise me?

Community manager's note: Check out How to fix a leaking toilet for expert advice. 

[EricL]

Hello @rosharch

Welcome to the Bunnings Workshop community. It's fantastic to have you join us, and thank you for sharing your question about how to detect a toilet leak.

The food dye technique is a tried and tested method for detecting leaks. You need to put in at least 25 drops of either the blue or green food dye to make sure the cistern is saturated. If you have a leak you'll see the water in the pan change colour. The testing period will usually last anywhere from 10 to 15 minutes and you'll be able to see the results.

If the bowl is anything other than clear water, then there is a leak in your cistern. I recommend changing the flushing seal at the bottom of the flush assembly. My number one tip is to bring the flushing assembly with you to the store to make sure that you purchase the correct fitting seal.

If you need further assistance, please let us know.

Eric

[rosharch]

Thank you for the reply. Is the colour of the dye important? I have red at home...

[MikeTNZ]

Hi @rosharch,

You maybe could try using something like good old Harpic Bloo toilet cleaner, I'm not sure if you can still buy that in Australia, you can here in New Zealand.

Two things that you can check however, that will cause this to happen and waste a lot of water during the day and night.

Is the cistern the type that has a ball-cock valve assembly inside it?

A picture of the internals of the cistern you have would be awesome!

This is recognisable by an arm with a big plastic ball at the end of a metal arm that comes out of the valve, where the water is fed into the cistern.

Does this close off, fully?, you will hear and see water issuing from the bottom of the valve, if this is not the case.

If the valve doesn't fully close, either the ball has a hole on it and has let water in, meaning it doesn't float on top of the water anymore, like it should.

If the ball is actually floating and the valve is slightly open, allowing water to be fed into the cistern, you can try gently bending the arm upwards at it's centre point to close the valve.

If this still doesn't close the valve fully, there may be some grit or a small stone jammed in the valve itself, preventing the valve from closing.

Secondly, there may be a small stone or some grit under the actual flushing valve in the cistern itself, preventing it from fully closing, it doesn't take much at all to stop this from sealing and this will in turn keep the cistern filling to make up the loss of water that gets fed to the toilet pan, un-necessarily, I might add.

Try these simple things and get back to us as to how things went.

We're more than willing to help you out.

Cheers,

Mike T.

[EricL]

Hi @rosharch

The colour red will do just fine, blue and green are just suggestions. Make sure to try out @MikeTNZ's troubleshooting recommendations. If it's just a rock or debris that's caught on the edge of the flusher or the inlet valve that would save you a trip to the store.

Please keep us updated with your progress, we look forward to hearing that your cistern is fixed.

Eric

[rosharch]

Thanks for the detailed trouble shoot...it's not a ball valve. It's one I installed from Bunnings a couple of years ago...but I'm unsure where to look for grit?

 

 

[rosharch]

Hi thanks for the clarification. I'm not 100% sure where to look for grit or stones but to my eye there doesn't appear to be any. I attached pics of the valve in my reply to @MikeTNZ 

Meanwhile, here's the results of the dye test. I'd say we have a problem 

 

[MitchellMc]

Hi @rosharch,

It could be the inlet valve seal or the flush valve washer. Turn the water off at the mini cistern cock next to the toilet. This turns off the water to the cistern and eliminates the inlet valve as a consideration. If the dye continues to flow into the pan, you need to replace the flush valve seating washer. You must remove the flush valve assembly to access the washer at the bottom.

If the dye stops leaking into the pan after turning the water off to the cistern, it's the inlet valve seal. That's a simple fix. Just pop the black cap off the inlet valve on the right and replace the rubber valve. 

Given the flush valve's vintage, I suspect its washer is the culprit. Have a look to see if you can find some clips that, when released, allow you to pull the assembly out.

Let me know how you go, and I can guide you through the replacement process.

Mitchell

[rosharch]

Hi Mitchell,

Thanks for the detailed reply!

Turning off the water to the cistern resulted in almost all the red dye remaining in the cistern itself. There was some small amount of red dye in the bowl but seeing as before it was a continuous flow of dark red, I'm going with inlet valve seal.

Do you think it needs replacing seeing as I bought the entire valve and seal from Bunnings only a year ago? Is it perhaps just an adjustment that needs to be made?

  

[KatieC]

Hi @rosharch,

I am so glad to see that @MitchellMc @EricL and @MikeTNZ were able to help with your toilet seal issue. Eric will be online later this afternoon and will be able to further assist you with your Bunnings valve and seal question. If you ever have further D.I.Y. questions, feel free to reach out.

Katie