Leaking Toilet Pan Connector: How to Fix It
By Emergency Plumb,
Water at the back of the toilet that appears each time you flush is the classic sign of a failed pan connector. It is a cheap part, but leaving it means dirty water soaking into the floor every flush.
Short answer: Dry the area, flush, and watch the joint where the toilet outlet enters the soil pipe. If water appears there after the flush, the pan connector’s seal has failed or the pan has moved. Replace the connector, and fix the pan firmly to the floor so it cannot work loose again.
What fails, and why
Pan connectors are sealed with rubber fins or a ring that grip the toilet outlet and the soil pipe. Over the years the rubber hardens, and every time the pan rocks slightly the seal opens a fraction. A pan that is not screwed down firmly, or a floor that flexes, wears the seal out much faster. A connector can also be pushed partly out of the soil pipe when the pan is knocked or moved.
Confirming the source
- Dry the floor, the back of the pan and the pipes completely.
- Lay a sheet of kitchen roll under the joint.
- Flush, then watch with a torch for a minute.
Water at the outlet or the soil pipe after the flush means the connector. Water running down from the cistern means the cistern-to-pan seal or the supply joint instead. Constant dampness without flushing usually means the supply pipe or valve.
The repair
The water is turned off and the cistern drained, then the pan is unscrewed from the floor and pulled forward off the old connector. The new connector, flexible or rigid depending on how well the pan lines up with the soil pipe, is pushed fully onto the soil pipe and the outlet, the pan is pushed back and screwed down firmly, and the joint is tested with several flushes. If the floor under the toilet has been wet for a long time, the boards are checked as well.
While it is apart
Check the pan for cracks around the outlet and the fixing holes, and replace the cistern-to-pan seal on a close-coupled toilet if it is hard. It costs very little to change them while the toilet is already off the wall. Our guide to a running or weak-flushing toilet covers the other common leaks, and our toilet repair and installation service replaces connectors at £99 for the first hour and £49 per additional half hour, plus parts.
Questions people ask
What is a pan connector?
The flexible or rigid sleeve that joins the toilet's outlet to the soil pipe in the wall or floor. It has rubber fins or a seal at each end that grip the outlet and the pipe.
How do I know the leak is the pan connector?
Dry everything, then flush and watch the back of the pan with a torch. Water appearing at the outlet or the soil pipe straight after a flush points at the connector. Water that is there all the time, flushing or not, is more likely the supply to the cistern.
Can I replace a pan connector without removing the toilet?
Sometimes. With a short flexible connector and enough room, the pan can be unscrewed from the floor, slid forward a little and the connector changed. A rigid connector, a cemented pan or a tight space usually means taking the pan out completely.
Can I just seal it with silicone?
Silicone smeared around a connector rarely holds, because the joint moves every time someone sits down. It also makes the proper repair harder. Replace the connector instead.