A toilet that leaks or runs is an easy homeowner fix—if you know how to diagnose the trouble. ID parts and problems with this handy guide, and hit the hardware store with confidence.
Know Your Parts to Fix a Leaking Toilet
Replaces water in bowl after flush. If toilet runs intermittently, check that tube’s end is above water level in tank.
On/off valve regulated by float ball fills tank and bowl after flush. If toilet runs intermittently, ball cock could be faulty and may need to be replaced.
When it comes time to retire an old ball-cock flush mechanism, the all-in-one plastic replacements stocked by home centers make for an easy fix. Float-cup mechanisms go in quickly and adjust easily for simple repairs.
Shuts off ball cock when water filling tank reaches correct level.
Opens flapper at beginning of flush. If toilet runs constantly, check that chain isn’t too short or long, thus interfering with flapper closing.
Prevents tank from overflowing. If tank water is constantly draining into tube, bend arm of float ball down slightly or lower float cup on replacement fill-valve assembly.
Lifts to let tank water flow into bowl. If toilet runs intermittently, scrub mineral deposits off it (or flush-valve seat under it) to tighten seal. If that doesn’t help, replace it.
Seals connection between tank and bowl.
Seals connection between bottom of toilet and drain. If water leaks out base of bowl, replace ring.
Holds bowl to flange. If toilet rocks, tighten nuts attached to these bolts. To avoid cracking bowl, secure no more than a quarter-turn past finger-tight.
Anchors toilet to floor and connects to drain pipe.