Dux cistern seating washer

In all the 4 cisterns that I have, the seating washers cannot be replaced because the plastic clip/ round thing that holds the washer in place appears be glued there.
And there appears to be a basic design flaw in that water can creep above the washer, through the hole in it, and down to the toilet.
So there is a constant 1 cubic metre leak every month, for 20 years, costing $720 in water charges.

https://www.bunnings.co.nz/fix-a-loo-seating-washer-suits-caroma-dux_p00143455

The part that holds the washer is usually a bayonet fit onto the washer seat - on older type cisterns.

I'm talking about the plastic part that holds the washer on, not the whole unit.

I'm sorry to hear about your problem with the Dux cistern seating washer. It sounds like a frustrating situation, especially with the constant leak that's costing you so much money in water charges. However, I think I might have a solution for you.

Have you tried contacting Dux or their customer support team? They might be able to provide you with replacement seating washers or even a solution to fix the issue you're having. Alternatively, you could also try reaching out to a plumber or someone who is experienced in fixing cisterns.

Regarding the plastic clip/round thing that holds the washer in place, it's possible that it might be glued in place for added stability. However, it should still be possible to remove it and replace the washer. You might need to use a bit of force or a special tool to remove the clip, but it should be possible.

As for the design flaw you mentioned, it's not uncommon for water to seep through small gaps or holes in cisterns. However, there are ways to prevent this from happening. One solution could be to add a layer of silicone sealant around the seating washer to create a watertight seal. Another option could be to replace the entire cistern with a newer model that has better design features and is more water-efficient.

In terms of which brand or product to choose, it really depends on your personal preference and budget. It's always a good idea to do some research and read reviews from other customers before making a purchase. Some brands and products that you might want to consider include Caroma, Roca, Kohler, and American Standard.

In conclusion, I hope these suggestions have been helpful in addressing your issue with the Dux cistern seating washer. Remember, it's always a good idea to consult with professionals or seek help from the manufacturer when dealing with plumbing issues.

I've just done that. It still leaks. They always leak.

Have you made sure its seated right in the groove? Sometimes it needs some prodding to make it fit correctly.

The other possibility is the surface the washer sits on, at the outlet. is it nice and smooth?

Yes the surface is smooth. I reckon the water seeps over the top of the washer and through its hole.
I shall glue a new washer in place tomorrow.

Is the problem the fill valve washer - overfilling the cistern so it overflows down the pipe at the center of the washer? If this is the problem, the cistern will not leak down the bowl for a few minutes, until it overfills.

do not do that.

your problem is that the fix-a-loo washers are the wrong size.
bunnings has another brand that is the right size. its only a few mm bigger.
edit: kinetic brand caroma and dux cisterns.
also you need to spin the washer around for it to sit right. there is a utube vid from the manufactures on how to do it.

This one here fits correctly:
https://www.mitre10.co.nz/shop/plumb-it-cistern-washer-old-dux/caroma-black/p/289654

Agree with #10. Sometimes the washer is the incorrect size, even though it's advertised as being specific to your brand of toilet.
I've also encountered this with the Plumb-It brand from Mitre 10.

just pull the washer over. not had to do