Toilet Leaking From the Base? Find Where It Starts
By Emergency Plumb,
A puddle round the foot of the toilet almost never comes from the base itself. It is water from somewhere higher up that has run down the pan and collected on the floor, and finding where it starts is most of the job.
Short answer: Dry the toilet, the pipes and the floor completely, put dry tissue at each joint, then flush and watch. Water only after a flush points to the pan connector at the back. Water that appears without flushing points to the cistern, its bolts or the supply pipe. A film of water on the outside of a cold pan in winter can simply be condensation.
Do this first
Stop using that toilet if the water looks dirty, and wipe it up with gloves on. If it is clean water that keeps coming, close the small isolating valve on the pipe to the cistern with a flat screwdriver, or turn the stopcock off. Keep the floor dry and look at the ceiling below if you live upstairs.
The pan connector
The joint between the back of the pan and the soil pipe is the commonest cause of a leak that shows only when you flush. Older connectors were rubber cones or putty joints that harden and crack; newer push-fit connectors can be knocked out of line when the pan moves. A connector that has failed usually leaves a dirty tide mark behind the pan. Our guide to a leaking toilet pan connector goes into the repair in detail.
The cistern and its bolts
On a close-coupled toilet the cistern sits on the pan with a large rubber doughnut seal and two or three bolts with washers. When any of those wear, water seeps out every time the cistern refills, runs down the back of the pan and arrives at the floor. A cistern that drips without being flushed is covered in toilet cistern leaking.
The supply and the isolating valve
The pipe feeding the cistern can weep at its compression nut or at the small isolating valve. These drips are slow, so they are often the last thing anyone checks. Wipe the pipe and hold tissue under each joint for a few minutes.
Condensation
A cistern full of cold mains water in a warm, steamy bathroom can sweat enough to drip. It is clean, it covers the whole outer surface evenly and it is worse after showers. Better ventilation cures it; nothing needs repairing.
A cracked pan
Rarely, the ceramic itself has a hairline crack, often from a heavy object dropped in it or a bolt overtightened. That water appears from one spot on the pan and does not stop. A cracked pan is replaced, not repaired.
When to call us
If you cannot see where it starts, if the floor feels soft, or if water is coming through the ceiling below, call 07861 933265. We charge £110 for the first hour and £45 for each half hour after, plus parts, with no call-out fee, and a like-for-like close-coupled toilet swap in the same position is £245 labour. For other toilet and shower faults see bathroom repairs and fault finding.
Questions people ask
Why is my toilet leaking from the bottom when I flush?
If water appears only when you flush, the pan connector at the back of the toilet is the usual suspect. It is the rubber or plastic joint between the pan outlet and the soil pipe, and when it perishes or slips, each flush pushes a little water out behind the pan.
Can a toilet leak at the base without being flushed?
Yes. A steady drip from the cistern, its bolts or the water supply will run down the back of the pan and collect at the base, so it looks like the toilet itself is leaking. Dry everything and watch where the first drop forms.
Is a small leak around the toilet base urgent?
It is worth fixing within days, not weeks. Dirty water soaks into chipboard and joists, and in a flat it can come through the ceiling below long before you notice anything in your own bathroom.
Will sealing round the base with silicone stop it?
No. Silicone round the foot of the pan hides the leak and traps the water under the toilet, where it rots the floor. The fix is at the joint that is leaking, not at the base.