Geberit Outlet Valve Washer 816.418.00.1

Is your toilet leaking water into the bowl? If your toilet is over 10 years old and you see a constant ripple of water in the pan, the outlet valve seal has likely bubbled or warped.

The Match: This 816.418.00.1 washer is the correct fix for Geberit Kappa (240.638.00.1) and Geberit UP170 (240.502.00.1) in-wall cisterns, as well as almost all Back-to-Wall (BTW) suites from Villeroy & Boch, Parisi, Duravit, Laufen, and GSI.

The Exception: This does NOT fit the Geberit Sigma 241.290.00.1 valve (which requires the smaller 241.291.00.1 seal).

Genuine Geberit Spare Part: 816.418.00.1 When a toilet “ghost flushes” (refills itself every hour without being used), it is usually because this flat rubber washer has failed. Over time, chemicals in the water cause the rubber to blister, preventing the valve from sitting flush against the base.

Suits Major European Brands: If you have a Back-to-Wall toilet (where the ceramic tank is visible outside the wall) from any of the following brands, this is almost certainly the washer you need:

Villeroy & Boch: (Architectura, Subway, O.Novo). NOTE, this does not Subway 2.0, Subway 3.0 and O Novo 2.0. The Back to Wall Toilet use the Omina Outlet Valve
Parisi: (Envy, Sorrento, Quasar)
Duravit: (Starck 2, Starck 3, Darling New)
Laufen & GSI models.

Kappa vs. Sigma: Which one do I have? A quick way to tell if you need this 816.418.00.1 washer (for Kappa) or the smaller Sigma washer is the “Lid-Lift Test”:
Kappa (This Washer): If you lift your toilet seat lid and it partially or fully covers the flush plate on the wall, you have a “Low-Height” Kappa cistern. This is the correct washer.
Sigma: If the flush plate sits high enough on the wall that the toilet lid doesn’t come near it, you likely have a Sigma cistern and need the smaller 241.291.00.1 seal.

Q: How can I identify my Geberit cistern without opening the wall?
A: Use the “Lid-Clearance” method. Because the Kappa (240.638.00.1) cistern is designed for low-height installations (like under a window or a shelf), the flush plate is often installed quite low. If your toilet seat lid obscures the plate when lifted, you have a Kappa system and require this 816.418.00.1 seal.

Q: Does this fit Back-to-Wall (BTW) toilets where the tank is outside the wall?
A: Yes. If you have a floor-standing toilet with a visible ceramic tank (common in brands like Parisi, V&B, and Duravit), Geberit uses the same outlet valve assembly that takes this 816.418.00.1 washer.

Q: What happens if I use the wrong washer?
A: If you use this Kappa washer on a Sigma valve, it will be too large and may catch on the housing, causing the valve to hang open. If you use a Sigma washer on a Kappa valve, it won’t create a full seal, and the “ghost flushing” will continue.

“Why Replace at 10 Years?”
The 10-Year Service Rule: In Australia’s varied water conditions, Geberit rubber seals typically last between 8 and 12 years. If your toilet was installed a decade ago and you’ve noticed a slow, silent drip into the bowl, replacing this seal is the first step. It is a simple DIY task that involves clicking the valve out of the cistern—no tools are usually required.