Running toilet parts
Hub
Quiet fixes for a toilet that will not stop running: flapper, chain, water level, and when a fill valve swap is the next honest step.
Check toilet fill valve float height
When the toilet flapper looks fine but the toilet keeps running, set the fill-valve float so water stops below the overflow tube.
How Much Slack Should a Toilet Flapper Chain Have? How to Adjust It
Toilet flapper chain should have about 1/2 inch of slack when the flapper is closed. Here is how to adjust it, trim it, and fix a toilet that still runs or flushes weak.
Running toilet — check the supply valve for drips after a fix
Running toilet repair tip: after you reopen the toilet supply valve, check the valve stem for a slow drip before you put the tools away.
Running toilet — flush debris out of the fill valve
Toilet keeps running or hissing after a good flapper? Grit in the fill valve can keep it from closing. Flush the valve briefly with the cap off.
Running toilet — skip tank tablets that can wear the flapper
Running toilet tip: some drop-in tank cleaning tablets can soften or warp the rubber flapper over time. Clean the bowl instead and keep the tank plain.
Running toilet — wipe the flush valve seat under the flapper
Toilet keeps running with a good flapper? Mineral grit on the flush valve seat can break the seal. Shut off water and wipe the seat smooth.
Toilet flapper — check a twenty-minute pencil-mark drop
After a quiet fill, pencil-mark the toilet tank waterline and check a twenty-minute drop to spot a slow toilet flapper leak — one beat.
Toilet flapper — dual-flush chain tangle keeps toilet running
On dual-flush tanks, a tangled flapper chain can hold the toilet flapper open so the toilet keeps running even when the trip lever feels fine.
Toilet flapper — hold it closed to confirm a leak
If a toilet keeps running, hold the toilet flapper closed by hand to confirm a flapper leak before you replace parts — one beat.
Toilet flapper — pencil-mark the tank waterline after a quiet fill
After the tank goes quiet, pencil-mark the waterline so you can see if a slow toilet flapper leak drops the level — one small beat.
Toilet flapper — seat it evenly with no twist in the chain
A toilet that keeps running after a new flapper often has a twisted chain holding one side off the seat — untwist and seat the toilet flapper evenly.
Toilet flapper — set chain slack to about one finger width
After a toilet flapper swap, set chain slack to about one finger width so the toilet keeps running neither from taut lift nor from excess slack tangle.
Toilet flapper — shut the water off and flush before a swap
Before you replace a toilet flapper, turn off the supply valve and flush to drain the tank, so you can work dry and see how the flapper seats.
Toilet flapper — tighten the handle nut for partial lift
When a toilet keeps running with a good toilet flapper, a loose handle nut can hold the flapper slightly open. Snug the nut — do not crush the tank.
Toilet flapper fine — bent trip lever needs a kit not just a flapper
When a toilet keeps running after a new toilet flapper, a bent trip lever can hold the flapper open. Replace the lever kit instead of stacking more flappers.
Toilet flapper fine — dual-flush float can still keep it open
On dual-flush toilets, the half-flush float can interact with a good toilet flapper and leave the toilet keeps running. Check float travel before another flapper swap.
Toilet flapper fine — fix handle bushing sideways play
When the toilet keeps running after a good toilet flapper, sideways handle play from a worn bushing can lift the chain. Snug the bushing before another flapper swap.
Toilet flapper fine — keep refill tube above waterline
If the toilet flapper seats but the tank still misbehaves, clip the anti-siphon refill tube above the waterline to stop sneaky siphoning.
Toilet flapper path — match fill valve to left vs right tank hole
Before you buy a fill valve on a toilet keeps running path, match left vs right tank hole so the new valve clears the flapper and trip lever.
Toilet ghost flushes or refills on its own
Stop intermittent phantom flushes: check the refill-tube siphon, dye-test a slow flapper leak, and know when a fill valve is next.
Toilet Keeps Running? How to Check and Fix the Flapper
Toilet keeps running? Test the flapper with food coloring, check the chain and seat, then clean or replace it with the right 2-inch or 3-inch size.
Toilet runs after the water was shut off — reset the flapper
Toilet keeps running after a water shutoff or plumber visit? Grit and air can shift the flapper. Flush, check the seat and reset the chain.
Toilet still runs after a new flapper
Why a new toilet flapper can still let the tank run — size and style, chain slack, pitted seats, fill-valve height, and bleach tablet damage.
Toilet Water Running Into the Overflow Tube? How to Fix It
Toilet water spilling into the overflow tube means the tank fills too high or the fill valve won't shut off. Lower the float, test the valve, and fix it.