How-To GuidesToilet repair basics
How to identify the three common toilet faults, which ones are simple part swaps, and which ones mean calling a plumber.
By Elijah Canfield, Founder, Hire Best Pros · Updated August 27, 2026
Elijah Canfield is the founder of Hire Best Pros. He writes and edits the site's consumer guides, with a focus on how home service and moving projects are priced, scoped and compared.
A toilet that runs constantly usually has a failed flapper or a fill valve set too high. A weak flush is often blocked rim holes or a partial clog. Water on the floor is the one to take seriously, because it can mean a failed wax ring, a cracked tank or a supply line, and it damages the subfloor while you decide.
Key points
- A running toilet wastes water continuously and is usually a cheap part.
- Rocking on the floor means the flange or bolts need attention, not caulk.
- Sewage smell or water at the base is a call, not a project.
The toilet that will not stop running
Lift the tank lid and watch a cycle. If water flows over the top of the overflow tube, the fill valve is set too high or has failed. If the tank drains slowly with no flush, the flapper is not sealing. Both are inexpensive parts, but match the model before buying.
Weak or incomplete flush
- Check the chain length so the flapper opens fully
- Confirm the water level reaches the marked fill line
- Clear mineral deposits from the rim holes under the bowl edge
- Rule out a partial clog in the trap or the branch drain
When to stop and call
- Water pooling at the base after every flush
- A toilet that rocks or has loosened from the floor
- Repeated clogs across multiple fixtures, which suggests a main line issue
- Any sewage odor that persists after cleaning
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