tundish location for condensate drain

saw this on youtube the other day, confused the crapout of me.
if you look at the one with the green tick, im thinking what is stopping the water going up and out into the cupboard there is the sinks are full and you let them out quick?
if that is a one way system there at the tundish, what happens if it deteriorates and fails? floods the cupboard?

Quote:

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Originally Posted by wozzzzza

if you look at the one with the green tick, im thinking what is stopping the water going up and out into the cupboard there is the sinks are full and you let them out quick?

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If that happens then there are problems with your drains that need to be fixed.
The design cannot compensate for every single problem that may happen.

Quote:

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Originally Posted by wozzzzza

saw this on youtube the other day, confused the crapout of me.
if you look at the one with the green tick, im thinking what is stopping the water going up and out into the cupboard there is the sinks are full and you let them out quick?
if that is a one way system there at the tundish, what happens if it deteriorates and fails? floods the cupboard?

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Yep not good.
Best practice is for the tundish/open drain as high as possible under the benchtop.
But of course as above, that will not compensate for blockages in the system.

Old post I know but I might as well answer it.

Not 100% sure but I think the tubelike thing immediately below the green tick is a waterless trap. Basically it’s a one-way valve for both gas and liquids. That’s what we have below our tundish (also in a vanity) and it has prevented flooding on a couple of occasions.

https://plumbingsales.com.au/waterle...sing-50mm.html

They’re good things to know about. They can solve many space and access issues.