The siphon is a key component of the wastewater drainage system, installed under sinks, washbasins, showers and bathtubs. It prevents unpleasant odors from rising and ensures proper water drainage. When a leak occurs, it can cause damage and make the system uncomfortable to use. An effective repair and a few precautions can prevent the problem from recurring.
Identifying the cause of a siphon leak
Before intervening, it’s essential to understand why the siphon is leaking. The most common causes are :
- A worn or incorrectly positioned seal, no longer guaranteeing a watertight seal.
- Insufficient or excessive tightening of fastening nuts, which can lead to leaks.
- A build-up of waste or limescale, causing clogging and water overflow.
- A crack in the siphon, due to wear or impact.
A visual inspection can often pinpoint the source of the problem.
Repairing a leaking drain
Seal replacement
In most cases, a leaking siphon is caused by a damaged seal. To replace it :
- Remove the siphon by unscrewing the nuts by hand or with pliers.
- Check the condition of the gasket and replace it with a new one of the same diameter.
- Clean the bearing surfaces before repositioning the gasket.
- Screw the siphon back on, but don’t overtighten to avoid crushing the seal.
Checking and adjusting tightening
An incorrectly tightened siphon can cause leaks. After reassembly, tighten the nuts firmly but lightly. Overtightening can crush the seal and cause leakage, while undertightening can allow water to pass through.
Cleaning the siphon and pipes
A clogged siphon can cause water to back up, leading to leaks. Regular cleaning is recommended:
- Dismantle the siphon and remove any accumulated residues (hair, grease, waste).
- Rinse with hot water to dissolve soap and lime deposits.
- Check and clean screw threads before reassembly.
Siphon replacement in case of cracks
If the siphon is cracked or damaged, simple plugging will not suffice. It must be completely replaced:
- Choose a siphon of the same diameter and compatible with your installation.
- Remove the old siphon by unscrewing the fittings.
- Fit the new siphon, inserting new gaskets and tightening the nuts.
- Test the installation by running water and checking for leaks.
Prevent recurring leaks
To prevent the problem from recurring frequently :
- Check seals regularly and replace them at the first sign of wear.
- Do not overtighten fittings to avoid damaging threads and seals.
- Clean the siphon every three to six months to prevent clogging and residue build-up.
- It’s best to replace with a quality trap, as lower-end models wear out more quickly.
Call on Leader Services
If you have recurring leaks or need a lasting repair, Leader Services can intervene quickly to identify and solve the problem efficiently. Our experts will replace and maintain your traps to ensure optimum drainage.
- Discover our plumbing services: Leader Services – Plumbing
- Need a professional? Contact us here: Leader Services – Contact
Conclusion
A leaking siphon can be caused by a worn seal, incorrect tightening or an obstruction. By replacing the seals, adjusting the fittings correctly and cleaning the trap regularly, you can avoid recurring problems. If the leak persists, a complete replacement or the intervention of a professional will guarantee a reliable, long-lasting solution.
