Water on the bathroom floor near the toilet is never something to ignore. Here's how to find where it's really coming from.
First, find the source
Dry the floor and the whole toilet completely, then watch.
- Water appears at the base after flushing: most likely the seal under the toilet.
- Water drips from under the tank: the tank-to-bowl connection.
- Water on the floor near the wall: the supply line or shutoff valve.
- The whole outside is wet: could be condensation ("sweating"), from cold water in a warm, humid room. It's more common in summer and monsoon season.
Food coloring test: add a few drops of food coloring to the tank (not the bowl). Don't flush. If colored water shows up in the bowl after 15 to 20 minutes, the flapper is leaking inside. That doesn't wet the floor, but it wastes water and makes the toilet run.
Leaking at the base
Worn or broken wax ring
Under every toilet is a seal, usually a wax ring, between the toilet and the drain pipe. When it fails, water seeps out when you flush, and you may smell sewer gas. The fix is to pull the toilet and reset it with a new seal.
Loose toilet
If the toilet rocks, the bolts holding it to the floor may be loose, which can break the seal. Snug them gently: overtightening can crack the porcelain. If it was rocking for a while, the seal is probably damaged and should be replaced.
Cracked toilet
A hairline crack in the bowl or base can leak slowly. Cracked porcelain can't be repaired; the toilet needs to be replaced.
Leaking from the tank
- Tank-to-bowl bolts or gasket: water drips from under the tank, especially after flushing. The gasket and bolts can be replaced.
- Supply line: the flexible line from the wall to the tank can loosen or wear out. Replace it rather than over-tightening it; a burst supply line floods fast.
- Fill valve: if water rises above the overflow tube or the tank keeps refilling, the fill valve may need adjusting or replacing.
- Shutoff valve: the valve on the wall can drip at the stem. If it's stuck or leaking, have it replaced.
Why not to wait
- A slow leak at the base soaks the floor, grout and baseboards, and can damage the subfloor in a second-story bathroom.
- A failed seal can let sewer gas into the house.
- A toilet that runs all day wastes a lot of water and shows up on your bill.
When to call a plumber
Call when water appears at the base after flushing, when the toilet rocks, when you smell sewer gas, or when a valve or supply line is the problem and you'd rather not risk a flood. If water keeps showing up and the toilet checks out fine, the leak may be elsewhere; see leak detection.
OX Plumbing resets and replaces toilets and answers 24/7. Our $99 service call covers the visit, the diagnosis and an upfront price.