Large Toilet Cistern Overflow Hole Blanking Plug — 3/4″ BSP (26mm Thread)

Large Toilet Cistern Overflow Hole Blanking Plug — 3/4″ BSP (26mm Thread)

Features

This premium toilet cistern overflow blanking plug is a specialized plumbing hardware spare engineered to safely seal unused or redundant overflow holes in ceramic or plastic toilet cisterns. While the vast majority of standard overflow blanks on the market utilize a smaller 1/2″ BSP fitting, this heavy-duty plug features an oversized 3/4″ BSP thread (measuring approximately 26mm in outside diameter). Moulded from robust, high-impact white polypropylene, the assembly includes a low-profile mushroom cap, a heavy-duty rubber sealing washer, and a secure back-nut. It provides a simple, permanent mechanical seal to neatly dress and waterproof unneeded cistern apertures during modern internal-overflow conversion upgrades.

• Oversized 3/4″ BSP male thread layout solves larger non-standard cistern hole issues
• Smooth white low-profile mushroom head blends cleanly into ceramic toilet suites
• Heavy-duty rubber sealing washer provides an immediate, watertight compression seat
• Engineered from rigid, high-impact polypropylene to resist cracking and degradation
• Complete kit supplied with a matching high-torque plastic back-nut for easy installation
• Universal fitment seals unneeded side holes when upgrading to internal overflow siphons
• Provides a neat, professional cosmetic finish that hides raw ceramic edge holes

Technical

• Brand: Wosherworld
• Part Number: STOP020
• Product Type: Toilet Cistern / Cold Water Tank Blanking Plug
• Thread Size: 3/4″ BSP (British Standard Pipe)
• Thread Outside Diameter: Approximately 26mm
• Material: High-Impact Polypropylene (Plastic)
• Colour: Gloss White
• Seal Material: EPDM Rubber Compression Washer
• Inclusions: Threaded Plug Body, Rubber Washer, Polypropylene Back-Nut
• Application Compatibility: Suitable for plastic, acrylic, and ceramic cistern bodies

Details

Sealing an old, oversized overflow hole is an absolute nightmare. Consequently, standard 1/2″ BSP plugs will simply slip straight through. Therefore, traders often try using messy silicone patches. However, these quick fixes fail under constant water pressure. As a result, slow tracking leaks develop behind the toilet. Eventually, this dripping water rots your floorboards.

Fortunately, installing this specialized toilet cistern overflow blanking plug solves this issue. Specifically, the wider 3/4″ BSP thread fits larger apertures perfectly. Additionally, the soft rubber washer compresses tightly against the cistern wall. Therefore, it creates a rock-solid mechanical seal. Consequently, you get a clean, permanent, and completely watertight repair.