Parts worth knowing
- Angle stop
- The shutoff valve on the wall or floor behind the toilet. Turn it clockwise to stop water to the tank.
- Fill valve
- The upright valve in the tank that refills it after a flush and shuts off at the set water level.
- Flapper
- The rubber seal at the bottom of the tank that lifts to flush and drops to hold water in.
- Flush valve
- The opening and overflow tube the flapper seals against.
- Wax ring
- The seal between the bottom of the toilet and the drain opening in the floor.
- Closet flange
- The fitting in the floor the toilet bolts to. A broken or loose flange lets the toilet rock.
Symptoms and likely causes
| What happens | Likely cause | Typical fix |
|---|---|---|
| Runs constantly | Worn flapper or water level set too high | Replace flapper or adjust fill valve |
| Refills by itself every so often | Flapper leaking slowly into the bowl | Replace flapper; check flush valve seat |
| Slow to refill or hisses | Fill valve worn or clogged with scale | Clean or replace fill valve |
| Water on the floor at the base | Failed wax ring or cracked bowl | Pull toilet and reset with new seal |
| Rocks when you sit | Loose bolts, uneven floor or broken flange | Repair flange, shim and reset |
| Drip from tank bolts or supply line | Worn tank gaskets or old supply line | Replace gaskets or supply line |
Check for a silent leak
Add color
Put a few drops of food coloring in the tank and do not flush.
Wait
Leave it for 15 to 20 minutes.
Look in the bowl
If color appears in the bowl, the flapper or flush valve is leaking.
Flush
Flush afterward so the coloring does not stain.
Repair or replace the toilet
Tank parts are inexpensive and usually worth replacing. A cracked tank or bowl, however, cannot be reliably repaired and should be replaced. Hairline cracks can leak slowly for a long time and damage the subfloor.
Some original toilets in older homes use much more water per flush than modern ones. If your toilet needs a major repair, replacing it with a current water-efficient model may be worth considering. Ask the plumber to check the flange and the floor under the toilet while it is off.
Questions for the plumber
- Is the floor or subfloor damaged under the toilet?
- Does the flange need repair, and how will you secure it?
- Would you replace the angle stop and supply line while you are here?
- Is replacing the toilet more sensible than repairing it?
Common questions
Is a running toilet urgent?
Not usually dangerous, but it can waste a lot of water. Close the angle stop between uses if you cannot repair it right away.
Why does water appear at the base only sometimes?
A failed wax ring often leaks only during flushing. Condensation on the tank in humid weather can also drip and be mistaken for a leak.
Can I just caulk around a rocking toilet?
Caulk can hide movement but not fix it. A rocking toilet can break the wax seal, so the bolts, flange and floor should be checked.
General information for La Palma, not a quote or professional advice. In an emergency, call 911.