How do I replace a leaking toilet pan connector?
The four connector types, which one to buy for the offset you actually have, and fitting a push-fit connection so it seals without silicone.
- Difficulty
- intermediate
- Time
- 1 hr 15 min
- Read
- 4 min
- Safety
- warning
Short answer
Pan connectors are push-fit and seal on soft fins, so they are fitted dry or with a little silicone grease — never with sealant. Identify whether you need straight, offset, flexible or ninety degree, pull the old one off, clean both spigots, and push the new one fully home on both ends. A flexible concertina is the last resort, not the default.
The pan connector is the sleeve joining the toilet's outlet to the soil pipe, and it is the thing that leaks when a toilet weeps at the back after flushing. It is a cheap part and the job is straightforward, and the two things that go wrong are choosing a flexible connector when a rigid one would fit, and trying to make a poor joint watertight with sealant. The drawing shows all four types with the two joints that leak.
Safety
You are opening a foul drain connection. Wear gloves, keep the room ventilated, and wash thoroughly afterwards. Never leave the soil pipe open and unattended — drain gases come back up it and it is an open route into the drainage system. Plug it with a cloth if you have to stop mid-job.
What you'll need
- A pan connector of the correct type
- Gloves and old cloths
- Silicone grease
- A bucket and a sponge
- A helper, to move the pan
Step by step
- Confirm the connector is actually the leak.Dry everything, then flush and watch the back of the pan with a torch. Water arriving at the floor behind the pan immediately on flushing is the connector. Water present without flushing is the cistern, the supply or condensation. This distinction saves taking a toilet off for no reason.
- Work out what alignment you need.Look at where the pan outlet is and where the soil pipe socket is. In line and close: straight connector. Offset by a fixed amount vertically or sideways: offset connector, which can usually be rotated to place the step where you need it. Soil pipe running down through the floor: ninety degree connector. Genuinely awkward and nothing else fits: flexible.
- Understand why flexible is the last resort.A concertina connector's corrugations catch paper and solids on the inside, so it is more likely to block, and a stretched concertina pulls constantly on both joints. It exists for the cases nothing else fits, not as a general-purpose part.
- Isolate and empty the toilet.Close the isolating valve. Flush and hold the flush to empty the cistern, sponge out the remainder, and bail and sponge as much water as you can out of the pan trap. Whatever is left will come out on the floor when the pan moves.
- Free the pan.Undo the floor fixings — usually two screws through the pan foot, sometimes hidden under caps. Cut through any silicone sealing the pan to the floor. Then rock the pan gently backwards to break the connector's grip, and draw it forwards off the soil pipe.
- Plug the soil pipe immediately.Push a rag firmly into the open soil pipe as soon as the pan is clear. It stops the smell and stops anything falling in. Do not leave the room with it open.
- Clean both spigots properly.Scrape old sealant, scale and debris off the pan outlet and out of the soil pipe socket. The connector's fins seal against those surfaces and cannot do it over a crust. Check the pan spigot for chips — a chipped spigot will not seal and is the reason some connectors keep leaking.
- Fit the connector to the pan first.A smear of silicone grease on the fins, then push the connector fully onto the pan outlet until it is home. Working on the pan while it is out in the room is far easier than fitting the connector into the soil pipe and then trying to line the pan up with it.
- Offer the pan up and push it fully home.Take the rag out of the soil pipe, line the connector up squarely with the socket, and push the pan straight back in one movement. Do not twist it into place — twisting rolls the fins. The connector must go fully home, not most of the way.
- Check the pan sits level before fixing it down.A pan that rocks will work the connector loose within months. Pack the base with plastic shims if the floor is uneven, then fix down gently — never tighten a floor fixing to pull a pan down onto an uneven floor.
- Test with several flushes and a full bucket.Dry everything, flush several times and watch the joint. Then tip a full bucket down the pan quickly, which loads the connector far more than a flush does and finds a marginal joint that a flush does not.
- Reseal the pan to the floor last.A bead of silicone around the base, leaving a small gap at the back so any future leak shows on the floor instead of being trapped under the pan.
Common mistakes
- Smearing silicone sealant into the connector joint — The connector seals on soft fins. Sealant stops the fins seating properly, and it welds the joint so the next person has to destroy it.
- Twisting the pan into place — Twisting rolls the fins over. Push straight in, squarely.
- Using a flexible connector because it is easier — It blocks more readily and pulls on both joints. Use the rigid connector that fits the geometry you actually have.
- Not pushing the connector fully home at the soil pipe — A connector half in seals on one fin instead of several, and it works its way out.
- Leaving the soil pipe open while you go and get a part — Drain gases come straight into the house and anything dropped in is gone.