Toilet Leaking — seal, tank

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   From a dry, stable position, note the leak rate, water level, sewage odor or contamination, floor condition, and whether the toilet is near electrical equipment; close the local water shutoff only if it is dry, accessible, and turns normally without force.

   Expected result: The leak stops when the shutoff is closed, continues with the valve closed, the valve is stuck, the bowl or tank is cracked, or water is approaching an electrical outlet or equipment.

   Next step: Keep the toilet out of use, keep people away from contaminated or wet electrical areas, and call a qualified plumber. Use qualified electrical or emergency help if water reaches electrical equipment or the fixture is actively flooding.

   Stop if: Do not force the shutoff, keep flushing, touch sewage or electrical equipment, or continue if porcelain is cracked, water is uncontrolled, or the floor is unsafe.

   Why this matters

   Why: A shutoff that stops the leak points toward the toilet's supply or tank water path; continued leakage can be residual water, a bowl or floor seal, a nearby pipe, or another source. A stuck valve, crack, contaminated water, or electrical exposure is not a routine adjustment.

2. Check 2

   With the water supply isolated when safe, use a dry cloth or flashlight from outside the fixture to identify the first wet point at the tank lid and valve, tank-to-bowl seam, supply connection, bowl base, floor, or nearby pipe; do not remove the tank, bowl, or access covers.

   Expected result: Water first appears at the supply connection, tank or tank-to-bowl seam, inside the bowl with no outside wetness, under the bowl base, or at a nearby wall or pipe.

   Next step: Photograph the first wet point and arrange the appropriate plumbing diagnosis. Keep the supply closed for an active external leak and do not apply sealant, overtighten fittings, or lift the fixture as a test.

   Stop if: Do not remove porcelain hardware, disconnect the supply line, scrape a floor seal, or continue where wastewater, a crack, structural movement, or electrical water exposure is present.

   Why this matters

   Why: The location separates supply-line or fill-valve work, tank seal or flush-valve leakage, normal internal bowl water, a bowl or floor-seal problem, and a separate plumbing leak. Water inside the bowl alone is not an external tank leak.

3. Check 3

   If the tank is intact and the area is dry, observe the water level relative to the marked waterline, whether water reaches the flush-valve overflow, whether the fill valve runs periodically, and whether the refill hose end is visibly below the waterline; do not reach into a powered or contaminated fixture.

   Expected result: The water level is above the marked line, water enters the overflow, the fill valve cycles periodically, the flush seal appears to pass water into the bowl, or the tank-to-valve or tank-to-bowl area is externally wet.

   Next step: Use only the exact model instructions for a safe water-level or refill-hose observation; otherwise leave the supply closed and call a plumber. Do not use in-tank cleaners, force a valve, remove the tank, or replace a seal without model confirmation.

   Stop if: Stop for a cracked tank, uncontrolled overflow, sewage contamination, wet electrical equipment, or any need to remove the tank or work inside an unknown pressure-assist assembly.

   Why this matters

   Why: A high level, overflow, worn or dirty flush seal, tight trip chain, or refill-hose placement can cause internal water loss and recurring fill. External wetness at the valve base or tank seam points toward a gasket, connection, cracked tank, or seal issue rather than ordinary bowl water.

4. Check 4

   From outside the fixture, inspect the wall shutoff, supply line, coupling, fill-valve shank, and surrounding floor for a first wet point, missing washer, kink, corrosion, spray, or leak that appears only while the valve is open; do not loosen a wet connection or use force.

   Expected result: The supply connection is dry, the line or coupling leaks, water is at the fill-valve shank, the shutoff will not close, or the leak continues with the shutoff closed.

   Next step: Keep the shutoff closed for an active supply leak and call a plumber. Do not overtighten, remove the line, or reopen the water repeatedly to reproduce a spray or leak.

   Stop if: Do not force a seized shutoff, touch contaminated water, work on a cracked porcelain connection, or continue if water is entering a wall or electrical area.

   Why this matters

   Why: A line, washer, coupling, fill-valve connection, or shutoff can leak independently of the tank seal. Continued leakage with the shutoff closed shifts concern toward residual water, the fixture body, floor seal, or an upstream or nearby pipe.

5. Check 5

   After the fixture is no longer being used and the area is dry enough to observe safely, check whether water appears at the bowl-to-floor perimeter after a flush, at the tank-to-bowl seam, or from a nearby wall or supply line; do not rock the bowl, lift it, or remove caulk or floor hardware.

   Expected result: The bowl base becomes wet after flushing, the tank-to-bowl seam becomes wet, the bowl rocks or porcelain is cracked, or water comes from outside the fixture.

   Next step: Keep the toilet out of use and call a qualified plumber for any base leak, rocking, crack, sewage odor, or unresolved external source. Protect the floor without sealing over the leak or moving the fixture.

   Stop if: Do not sit on or rock a damaged fixture, remove the bowl, scrape the floor seal, use the toilet with wastewater leakage, or continue near a wet electrical area.

   Why this matters

   Why: A base leak can involve a floor seal, bowl damage, drain connection, or a leak traveling from above; a tank seam points to tank hardware or gasket; a rocking or cracked fixture raises structural and sanitation risk. A nearby source is not fixed by replacing a toilet seal.

6. Check 6

   Record the toilet make and model if visible, one- or two-piece or pressure-assist style, first wet point, leak timing, waterline and fill behavior, supply shutoff response, tank-to-bowl seam, bowl base, nearby pipe, odor, contamination, crack, movement, and any recent installation or cleaning-product use.

   Expected result: The record supports a tank or flush seal, supply connection, tank-to-bowl gasket, bowl base or floor seal, cracked fixture, overflow, or nearby plumbing branch, or the source remains unclear.

   Next step: Keep the water supply closed when the leak is active or the shutoff is unreliable and arrange qualified plumbing service. Add cleanup or electrical help for contaminated water, structural damage, or water near power equipment.

   Stop if: Do not continue if the floor is unsafe, the water is contaminated, porcelain is cracked or moving, the leak is uncontrolled, or the next step requires removing the tank or bowl.

   Why this matters

   Why: A structured record helps the plumber choose the correct gasket, valve, supply, floor-seal, porcelain, or pipe inspection without guessing from the size of the puddle. An unclear or recurring leak should remain treated as active.