5-Pack 28mm Toilet Cistern Rubber Diaphragm Gasket Replacement

Stop Toilet Leaks Fast — 5-Pack Rubber Diaphragm Gaskets

Keep your toilet cistern working flawlessly with this 5-pack of durable rubber diaphragm gaskets. Designed to fit Siamp cistern fill valves, these replacement washers are compatible with ball valves and both bottom and side inlet filling valves — making them a versatile, must-have spare for any bathroom maintenance kit.

Key Features

• Wide Compatibility: Fits all Siamp packing valves, ball valves, and bottom & side inlet filling valves
• Precise Dimensions: 28mm overall diameter × 12.3mm depth — an accurate, snug fit for proper sealing
• Quality Rubber Construction: Made from durable rubber for long-lasting, water-tight performance
• Easy to Identify & Install: Easily recognisable shape makes DIY replacement quick and straightforward — no specialist tools required
• Value Pack: Comes with 5 gaskets so you always have spares on hand for future maintenance

Specifications

What's in the Box?

5 × 28mm Rubber Diaphragm Gasket Washers

Please Note

Actual colour may vary slightly from product images due to monitor display settings and lighting conditions. Please allow for minor measurement tolerances of ±1–2mm.

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For guidance on toilet maintenance and plumbing repairs, visit the U.S. Consumer Product Safety Commission – Home Safety Resources.

Learn more: Washer (hardware)

Frequently Asked Questions

Q: What size are these rubber diaphragm gaskets and will they fit my toilet cistern valve?

A: These gaskets measure 28mm in overall diameter and 12.3mm in depth. They are specifically designed to fit Siamp cistern inlet fill valves, including Siamp ball valves and both bottom and side inlet filling valves. Always confirm your valve brand and measurements before purchasing to ensure compatibility.

Q: Are these diaphragm gaskets easy to replace yourself?

A: Yes! The diaphragm gaskets are designed to be easily recognisable and straightforward to install. Simply turn off your water supply, remove the old worn gasket from the fill valve, and press the new rubber diaphragm into place. No specialist tools are needed, making it an ideal DIY bathroom repair.

Q: Why should I buy a 5-pack instead of a single gasket?

A: Cistern diaphragm gaskets are wear parts that may need periodic replacement. Having a pack of 5 means you're prepared for future maintenance without reordering, and it offers better value per unit. They're also great for landlords or property managers who maintain multiple bathrooms.