Ideal Standard A911940 Gear Box Rubber Sealing Washer

Summary

Ideal Standard A911940 Gear Box Sealing Washer

The Ideal Standard A911940 is a rubber sealing washer used within Trevi and Ideal Standard built in thermostatic shower valve gear box assemblies. It provides a watertight seal around the internal drive components to prevent leakage behind the faceplate and to maintain correct flow control performance.

Function

This washer sits inside the gear box mechanism and seals the spindle and housing interface. A correct seal prevents water bypassing the gear assembly and supports smooth handle movement during flow adjustment.

Confirmed Compatible Ideal Standard and Trevi Models

• A3700AA Trevi Outline built in thermostatic shower valve
• A5800AA Alchemy built in thermostatic shower valve
• E3115AA Trevi Traditional built in thermostatic shower valve
• L6709AA Trevi Outline built in thermostatic shower valve with BIV shower kit
• S7832AA Sandringham built in thermostatic shower valve

These models list A911940 as the correct sealing washer within their official spare parts breakdowns. Only use this washer where the valve documentation or existing component identifies the same part code.

Construction and Dimensions

The washer is produced from rubber suitable for shower valve operating pressures. Typical dimensions are approximately 3.2 mm thickness with an outer diameter of around 34.5 mm and an inner diameter near 26 mm, sized to fit the designated gear box recess.

When Replacement Is Required

Replace the sealing washer if water is present behind the trim plate, if moisture appears around the gear box area, or when carrying out a gear box service and the washer shows flattening or wear. Fitting the correct A911940 ensures proper sealing and helps maintain flow control performance.