Most leaky toilet tanks come from one of four parts: the flapper, the fill valve, the tank-to-bowl bolts and washers, or the supply line. Find the culprit with a dye test and a dry paper towel, shut off the water, then replace the worn part. A cracked tank cannot be fixed reliably, so the tank or the whole toilet gets replaced.
If water is coming from the base of the bowl, a shutoff valve is dripping, or the floor below is stained, stop and call. Our toilet repair page covers what a plumber does, and (215) 714-6692 reaches the 24/7 line if you would rather not take the tank apart yourself.
Rule out sweat before you buy any parts
In humid weather a cold tank collects moisture on the outside, and it drips onto the floor like a leak. If the whole tank wall is wet, the dye test below stays clean and the floor dries after you wipe the tank, the cause is likely condensation, not a failed part. Parts that fix a real leak will not fix sweat.
Four checks that find the leak in under an hour
Do these in order. Each one rules out a part and takes only a few minutes of hands-on time.
- The dye test for a flapper leak Put a few drops of food coloring in the tank and do not flush. Wait 15 to 20 minutes, per Aqua's leak guide. Color in the bowl means water is slipping past the flapper.
- The dry paper towel check Dry the outside of the tank, the bolt heads and the supply connection, then press a paper towel on each joint. The wet spot shows which joint is dripping.
- The listen test for a fill valve If you hear hissing after the tank is full, or water is trickling down the overflow tube, the fill valve or its float needs attention.
- The meter check for a hidden loss Turn off all water use, note the meter reading, then wait 20 to 30 minutes and look again. A meter that has moved likely means a leak, per Aqua's guidance.
Where the water shows up and what it usually means
Match what you see to the likely part before you shop. This saves a second trip to the store.
| Where you see it | Likely cause | Usual fix |
|---|---|---|
| Dye in the bowl, or the tank refills on its own | A worn or warped flapper, or a chain that is too tight | New flapper sized to the flush valve, chain with slight slack |
| Constant hiss, water running into the overflow tube | A fill valve that will not shut off, or a float set too high | Lower the float, or replace the fill valve |
| Drip where the tank meets the bowl, tank wobbles | Tank bolts, rubber washers or the large spud gasket | Replace the washers or the full bolt and gasket set |
| Drip at the line under the tank | A loose nut, a worn washer or an old supply line | Snug it a quarter turn, or fit a new braided line |
| Drip at the wall valve stem | A worn stem seal on an older shutoff valve | Call for a valve replacement, see faucet repair |
| Hairline crack with seepage | A cracked tank | Replace the tank or the toilet |
Turn parts by hand or with light wrench pressure. Porcelain cracks when bolts are overtightened.
Water on the bathroom floor?
Shut off the wall valve behind the toilet, then call. A dispatcher answers at any hour.
Replacing a flapper, the most common tank fix
A flapper swap is the easiest repair on this list and a good first job. Plan on about half an hour, longer if the old one is stuck.
Shut off the water and empty the tank
Turn the wall valve clockwise until it stops, flush, and sponge out what is left. Keep a towel under the supply line in case the valve drips.
Unhook the old flapper
Slip the flapper's ears off the pegs on the overflow tube and unclip the chain from the flush lever. Photograph how it was set, so the new one goes back the same way.
Match the size
Flappers come in different sizes, and one that is too small will not seal. Take the old one to the store, or measure the opening at the bottom of the tank.
Hook up the new flapper and adjust the chain
Clip the ears on the pegs and attach the chain with a little slack, about the width of a finger. A chain that is too tight holds the flapper open, and one that is too loose can get caught underneath.
Refill and retest
Turn the water on, let the tank fill, and repeat the dye test. If the bowl stays clear after 20 minutes, you are done.
Aqua Pennsylvania supplies water to most of Abington Township, according to the township. Aqua's published leak adjustment page states that Aqua does not offer leak adjustments in Pennsylvania, and Aqua's leak guide says a leak inside your home is the owner's responsibility. A running toilet can quietly add to your bill, so a quick dye test is worth doing before you ever see a high bill.
Aqua's Leak Repair Program helps customers on its low-income assistance plan with leaks such as a leaking toilet, but you must be enrolled in that plan first. If a bill looks wrong, ask Aqua at 877-987-2782 to confirm the meter reading and the billing period, and ask whether you qualify.
On permits, the township's code lists replacing a water closet, a lavatory or a sink among residential work that still needs a permit. A flapper or fill valve kit is not on that list. Ask Community Development at 267-536-1000, ext. 4, about your exact job, and if you replace the whole toilet, ask your plumber to handle the township side.
Source type: Aqua Pennsylvania leak guide, leak adjustment page and Leak Repair Program page, and Abington Township code and permit pages
Fix it yourself or call a plumber
Reasonable to do yourself
- Run the dye test and the paper towel check
- Replace a flapper or adjust the chain
- Adjust the float or replace a fill valve
- Swap a supply line when the wall valve turns freely
- Replace tank bolt washers with care
Better left to a plumber
- A wall valve that will not turn or drips from the stem
- A cracked tank or a leak at the base of the bowl
- Water stains on the ceiling below the bathroom
- A toilet that rocks or has a loose floor flange
- Replacing the whole toilet
When the tank, not the part, is the problem
A hairline crack in the porcelain will keep seeping, and sealants are not a dependable cure. Once the tank is cracked, plan on replacing the tank or the whole toilet. In a house built in 1956, the median year for Abington Township homes per Census estimates, the toilet and the wall valve are often original or close to it, so ask the plumber to check both while they are there.
If you suspect water is escaping somewhere you cannot see, a meter test and a closer look are the next step, which is what leak detection covers. We also take toilet calls from nearby towns such as Wyncote and Glenside. Call (215) 714-6692 if the floor is wet and you cannot find the source.
Leaky toilet tank questions from Abington homeowners
The most common cause is a flapper that no longer seals, or a chain that is too tight. A dye test in the tank confirms it. If color reaches the bowl after 15 to 20 minutes, replace the flapper.
A drip where the tank meets the bowl usually points to worn tank bolt washers or the spud gasket. Dry the area, press a paper towel on each bolt, and replace the washers or gasket set. Do not overtighten, since porcelain can crack.
Sealants sometimes slow a seep, but they are not a dependable repair on a pressurized, wet tank. Plan on replacing the tank or the whole toilet, and ask a plumber to check the wall valve while they are there.
Condensation covers the outside of the tank evenly in humid weather and does not come back once you dry it and the air cools. A real leak shows a drip at one spot, and the dye test shows color in the bowl.
Aqua's leak adjustment page says it does not offer leak adjustments in Pennsylvania. Call Aqua at 877-987-2782 to confirm your meter reading, and ask whether you qualify for its Leak Repair Program for assistance customers.
The township lists replacing a water closet as work that still needs a permit, but it does not list a flapper or fill valve kit. Call Community Development at 267-536-1000, ext. 4, and ask about your exact job.
Aqua's leak guide gives a window of about 15 to 20 minutes after adding food coloring to the tank. Do not flush during that time. Color in the bowl afterward means the flapper is leaking.