Hi, I recently installed a sit toilet, from the previous squat toilet.

There is a problem when it flushes. The water collectively COMES UP near the brim of the toilet, then is quickly sucked down, creating a big gargling noise... The one upstairs flushes fine... everything stays at the bottom, it doesn't all flow up to the brim before it is sucked down...

I am just worried that this sort of behaviour is gross when big business is done. Imagine floaters coming up near the brim, nearly overflowing! Afraid some remnants will be around after everything is 'sucked down'...

My contractor says it has to do with some S-Trap thing, that the manhole ( ? ) is too short... and it would be very hard to rectify this... have to dig into the bottom (meaning have to re-hack the tiles, etc).

I suppose there is no way to fix this... just that I don't have a good explanation for this from the contractor. Anyone here experience the same ordeal, after converting a squat toilet system to a sitting one? Is there any way to change this easier/

The model is a Johnson Suisse Como single flush.

Thanks!

Thanks to Zheilwane's insightful explanation, I now understand what the problem is!

Called my contractor to explain that it was a mistake on his part. Thankfully he has agreed to rectify the problem and remove the "S" trap from the previous squat toilet system!!!

He is just afraid the hacking might damage the Como washdown toilet. I hope it will be intact lah...

BTW this is how it looks like:



Quite pleased with the Johnson Suisse lab sink and Premtex tap fittings too. The toilet is supposed to look like a sterile surgical environment...



[PS - my contractor is actually a pretty good guy besides this problem...]

Was a bit disappointed that I got my toilets from other shops and not from this guy... almost a few hundred cheaper lah compared to places like Han Lim etc... (and no I do not work for this guy! I just knew these prices after asking about it from him...)...

I didn't take a video of it before, as it was dark and the lamp fixtures is still empty. However, I'll try to visit the house soon to see if it's still in the same condition. I really hope they have hacked everything lah by then !!!

The Como on the 1st floor, in comparison, flushes beautifully...

Unnecessary headache..

The toilet is re-done liao with no problems! I will try to take pictures/video if possible.

Love my contractor!