Testing a Toilet for Leaks to the Floor (Note: More advice and information is available in the book OnlinePlumbingAdvice.com)
Systematic testing is the key to testing for toilet leaks.
- Dry finger test the bottom of the tank.
- Dry finger test around the high areas of the bowl and high area around the supply line.
- Dry finger test the low area of the supply line and the shut-off valve.
- Dry finger test around the bowl where it touches the floor.
- Flush the toilet and repeat steps one through four.
- If there is enough space to slide newspaper under the toilet (without disturbing the toilet), do so and after the toilet is flushed see if the paper gets wet.
These six steps do not properly test the seal under the toilet (AKA the wax seal).
Sometimes, if the drain connection is not visible from below, the only way to check the wax seal is to take out the toilet or cut a hole in the ceiling.