This bit of kit fitted inside your WC makes it flush by lifting and dropping a large rubber seal over a hole in the base of the WC cistern. They use the downward water pressure of the full tank to keep the seal. Sometimes the rubber seal can wear or it can develop bubbling, either could be the reason for a failure leading to a leak, or, it could be down to debris that is in the cistern. Hither Green Plumbers can repair the siphon. This debris is usually the remnants of freshener block that are placed in the cistern. If you suspect that the siphon is the reason for the leak then:

1). Isolate the water supply.

2). Flush the water away.

3). Remove the cistern lid, then, remove the top of the siphon by turning and lifting it away. Sometimes clips are fitted, so if so press them in and remove the siphon. The design of these varies.

4). Turn the siphon over and visually check the rubber seal on the base, looking for bubbling. If it looks poor or is damaged then replace it with a new one from you local merchant. Make sure to take the whole unit for identification. The new on will probably need to be ordered so keep the old one for now. If the rubber looks fine, then check for debris.

5). Clean out the cistern as a matter of course. A Hither Green Plumber would carry out this action.

6). Fir the top of the siphon back on the base, either twisting or clipping as necessary.

7). Restore the water supply and visually check that the unit is now leak free. If you couldn’t replace the seal straight away and the toilet is still leaking a lot of water, then isolate the toilet until a repair can be done.


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