How to Replace a Toilet Siphon

When your toilet no longer flushes properly, it is possible that the siphon or its diaphragm has gone through wear and tear. In most cases, you would have to replace the entire toilet siphon to fix the problem. How you do this depends on the type of toilet that you have – close coupled or separate cistern and pan.

Replacing The Siphon In a Close-Coupled Toilet

This process involves more work since you need to detach the cistern from the wall completely, so you can reach the plastic nut that holds the siphon in place.

  1. Turn off the water supply
  2. Using a footprint wrench, disconnect the overflow pipe and water intake pipe.
  3. Using your hand or mole grips, unscrew the butterfly nuts that hold the metal bracket and a large rubber seal that keeps the cistern and pan together.
  4. Unscrew the screws that hold the cistern to the wall, then lift off the cistern so you can reach the plastic nut holding the siphon.
  5. Once you removed and replaced the siphon, follow the same steps backward to put together the entire cistern and pan.

How To Replace a Siphon In a Separate Cistern And Pan

This process is the more straightforward of the two, so you should get the job done without breaking a lot of sweat.

  1. Using a screwdriver, loosen the large plastic nut found under the cistern, which holds the water pipe in place.
  2. Once lose, you should see another nut that holds the siphon. Loosen this too, and then proceed to disconnect the siphon from the hook that keeps it attached to the flush lever.
  3. Replace the siphon, and follow the same steps backwards to get everything back in order.

Before doing any repairs on both types of toilet, it is important to turn off the water supply and empty the cistern. Flush the toilet until all stored water has gone down the drain. If needed, use a sponge to remove the remaining water. This is done to minimize mess while fixing your toilet.

Signs That Your Toilet Might Need Fixing, Including a Siphon Replacement

  • The toilet won’t flush. This can mean two things – the flush lever is not properly connected to the flushing mechanism in the cistern, or the flush diaphragm is split. Since the diaphragm is found inside the siphon, you can choose to replace the diaphragm alone or the entire siphon.
  • The cistern is constantly filling. It is possible that the float valve is faulty or that it has a poorly adjusted arm. This problem not only results in excess water, but also noisy operation of the toilet.
  • You need to repeatedly press the button or pull the lever to get the toilet to flush. In this case, the flap valve probably needs replacing.

How Much Does It Cost To Replace The Siphon?

If you have confidence in your handyman skills, buying parts is a lot cheaper than with labor cost combined. But even if you hire a plumber, replacing a siphon shouldn’t cost much. So, if a plumber charges you with exorbitant rates, look for other service providers.

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