Thomas Dudley Dudley Turbo S1-11 Siphon - 9 Inch

The Thomas Dudley Turbo S1-11 9 inch Siphon is a high-quality plumbing component engineered for ef...

Best current price£46.95from eBay

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eBayThomas Dudley S1-11 two Part 9 inch Turbo Lever Flush Syphon 318743
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B&QB&Q - Dudley Turbo S1-11 9" SiphonPspsy1318743
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The RangeThomas Dudley Dudley Turbo S1-11 9" Siphon - Pspsy1318743 - Ideal For Efficient Flushing - Green
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OnBuy.comThomas Dudley Dudley Turbo S1-11 9" Siphon - Pspsy1318743 - Ideal For Efficient Flushing 5013241686501
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Product Information

Full details

The Thomas Dudley Turbo S1-11 9-inch Siphon is designed for homeowners and professional plumbers seeking a reliable, high-performance flushing mechanism for residential and commercial cisterns. It excels at providing efficient waste removal and consistent operation, though it is specifically engineered for 1.5-inch (40mm) connections and may require careful measurement of your existing cistern height to ensure a proper fit.

All features

Model Part NumberPSPSY1318743
BrandThomas Dudley

Extended Product Information

FAQs

Is this siphon compatible with all toilets?

It is compatible with most high and low-level cisterns that accept a 1.5-inch (40mm) syphon thread.

Can I replace just the top half of the siphon?

Yes, the two-part design allows you to service or replace the top section without removing the base unit from the cistern.

What tools do I need for installation?

Typically, you will need a wrench for the back nut and a bucket to catch residual water, though hand-tightening is often sufficient for the plastic fittings.

Is this suitable for commercial use?

Yes, its robust construction is designed to withstand the higher frequency of use found in commercial environments.

What does the 9-inch specification refer to?

This refers to the height of the siphon, which must match the depth of your existing cistern to function correctly.

Troubleshooting

Water continues to flow into the bowl after flushing

Check if the siphon diaphragm is debris-free or worn; clean or replace the internal seal if necessary.

Weak or incomplete flush

Ensure the flush lever is correctly connected and providing the full range of motion required to trigger the siphon.

Leakage at the base of the cistern

Ensure the rubber washer is correctly positioned and the back nut is tightened evenly against the cistern wall.

Pros and Cons

Pros

  • Durable, long-lasting construction
  • Easy to service due to two-part design
  • Broad compatibility with standard 40mm cistern threads
  • Trusted brand reputation for plumbing components

Cons

  • Requires specific 9-inch sizing measurement
  • Installation requires access to the internal cistern
  • Professional plumbing knowledge recommended for airtight seals

Setup, Compatibility & Care

Before starting your installation, ensure the water supply to the cistern is completely isolated and the tank is drained. You will need to verify that your cistern diameter matches the 40mm (1.5 inch) thread standard.

  1. Remove the old siphon by unscrewing the back nut located underneath the cistern.
  2. Clean the mating surface on the cistern base to ensure a watertight seal.
  3. Insert the new S1-11 siphon, ensuring the sealing washer is correctly seated.
  4. Tighten the back nut by hand; avoid using excessive force with tools, which can crack the plastic or compromise the seal.
  5. Reconnect the flush lever and test for leaks before fully refilling the tank.

Regular care involves periodic inspection of the siphon's internal components for lime scale buildup, especially in hard water areas, which can be cleaned with a mild descaling solution.

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