[charvy]

I am fitting a Gerberit Duofix frame and cistern. Does it need to be vented?

[talaniman]

for Toilets > Geberit Duofix > Products , Geberit UK

Seems to hook up to your existing sewer line which is already vented, according to the installation video.

[Milo Dolezal]

Absolutely, it has to be vented. It is just another toilet, just different design. Are you installing it in place of regular, floor-mounted toilet ?

If you are installing it in place of floor mounted toilet than you will have to do some pipe relocating to fit the new frame. Both, floor and wall mounted toilets / vents install different way.

If you are outside US than Code may be different. Check with local Building Inspector to find out what is required for your area

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Milo