Introduction
A leaking toilet tank is a common problem that can often be fixed with some basic DIY troubleshooting and repairs. Water continuously leaking into the toilet bowl from the tank can lead to higher water bills, wasted water, and potential water damage if left unaddressed.
The most common causes of a leaking toilet tank are a faulty flapper valve, broken fill valve, loose tank bolts, or a bad tank-to-bowl gasket seal. Diagnosing the exact cause requires a methodical inspection of the tank components. Most fixes involve replacing inexpensive parts like the flapper or gasket. With a few tools and supplies, you can often stop a running toilet and prevent wasted water.
This guide walks through the step-by-step process of how to fix a leaking toilet tank through inspection, diagnosing issues, replacing worn parts, proper reassembly, and testing for leaks. With a methodical approach, you can troubleshoot a leak in your toilet tank and make the necessary repairs to stop water from continuously running into the bowl.
Turn Off the Water Supply
Before doing any work on the toilet tank, you'll need to shut off the water supply to the toilet. This prevents water from continuously flowing into the tank while you're trying to make repairs.
Locate the shutoff valve that controls water flow to the toilet. It's usually found on the wall behind the toilet or down near the floor. The shutoff valve will have a handle that turns clockwise to shut off water and counterclockwise to turn it back on.
Turn the shutoff valve clockwise as far as it will go. Flush the toilet one time after shutting off the water to empty water from the tank. This will help prevent spills when you remove the tank lid.
Some key things to remember when turning off the toilet water supply:
- Make sure you locate the correct shutoff valve. Homes often have multiple shutoff valves under sinks or supplying outdoor spigots. Shutting off the wrong valve could accidentally turn off water to other areas.
- The shutoff valve handle should turn easily. Don't force it if there's resistance. Forcing a rusted valve can cause it to break.
- Shut off the valve completely. Sometimes valves get stuck halfway and don't fully shut off the water.
Once you've turned off the water supply, you can proceed with inspecting and making repairs inside the toilet tank safely. Don't turn the water back on until all repairs are complete.
Flush the Toilet
Before inspecting the inside components of the toilet tank, flush the toilet to empty both the tank and bowl completely. This will remove the remaining water from the tank and allow you to access and inspect the internal workings.
To flush the toilet:
- Lift or push down the toilet handle to flush the toilet as you normally would after use. Let it flush fully.
- After the initial flush, flush the toilet again. Sometimes it takes two flushes to clear out all the water from the tank.
- Check that no water remains in the tank or bowl. Only once all water has emptied from the tank and bowl can you proceed to the next step of inspecting the tank components.
Flushing the toilet completely before disassembling the tank ensures you can thoroughly inspect the toilet's inner workings for leaks, damage or issues. If any water remains, it can obstruct your view and make it difficult to see all the tank components clearly.
Inspect Tank Components
Look inside the toilet tank and identify any issues that could be causing the leak. Carefully inspect each component inside the tank.
Check the tank itself for cracks or other damage. Tap the porcelain gently with a rubber mallet to listen for any hollow sounds, which may indicate small hairline cracks. Inspect the tank thoroughly on all sides and at the base. Cracks can allow water to leak out. The tank may need to be replaced if cracks are found.
Examine the chain, flapper, floats, and other internal parts. Look for corrosion, loose connections, worn or cracked components. Give each part a gentle wiggle to check for looseness. Replace any pieces that are severely corroded or worn. Tighten any loose nuts or connections.
Make sure the flapper valve seal looks intact and sits evenly inside the flush valve at the bottom of the tank. An issue with the flapper seal not making a tight connection could cause leaks.
Inspect where the tank bolts pass through the bottom of the tank. Look for moisture or lime deposits, which indicate leaks at the gasket seal. Check that the gasket is in place.
Thoroughly inspecting all tank components will help identify any issues that could be the source of the leak. Replace any faulty parts. Tightening connections and seals may also stop small leaks.
Replace Flapper Valve
The flapper valve at the bottom of the tank is responsible for sealing water in the tank. If it is worn out or leaking, it needs to be replaced.
Follow these steps to replace the flapper valve:
- Disconnect the flapper valve from the flush valve by removing the clip or chain that connects it.
- Remove the old flapper valve and inspect it. Look for cracks, warping, or mineral buildup which indicates it needs replacement.
- Bring the old flapper valve to the hardware store to ensure you get an exact replacement.
- Install the new flapper valve by connecting the chain or clip to the flush valve.
- Make sure the flapper is hanging straight down and creates a tight seal when the tank is full.
- Adjust the chain so there is about 1/2 inch of slack when the flapper is closed. This allows enough chain movement so the flapper can open fully when flushed.
- Test flush the toilet to ensure the flapper valve is sealing properly without any leaks.
Replacing a worn, leaking flapper valve is an essential step in stopping a leaking toilet tank. It is typically an easy and inexpensive fix that can prevent wasted water and frustration. Take time to find the correct replacement and make proper adjustments to stop the leak.
Replace Fill Valve
The fill valve is the mechanism inside the tank that refills the tank with water after you flush. It consists of a vertical tube with a float ball on the end.
Over time, minerals in the water can cause the fill valve to corrode or develop small leaks. If the fill valve isn't shutting off properly, it will lead to the tank continuously running and wasting water. A corroded fill valve also needs to be replaced to prevent leaks.
To replace the fill valve:
- Turn off the water supply and flush the toilet to empty the tank.
- Disconnect the supply line to the old fill valve and unscrew the lock nut connecting it to the tank.
- Remove the old fill valve and pull up on the overflow tube to detach it.
- Install the new fill valve through the hole in the tank and tighten the lock nut below to secure it.
- Reattach the overflow tube and supply line. Ensure the float ball is set to the correct level, about 1 inch below the top of the overflow tube.
- Turn the water back on and test the fill valve. Make sure it shuts off completely when the float ball rises with the tank water level.
- Adjust the float ball up or down as needed until the fill valve shuts off properly.
Replacing an old, leaking fill valve is a straightforward fix that can conserve water and prevent leaks. With a new fill valve installed, the tank should function quietly and efficiently once again.
Check Tank Bolts
The tank bolts help secure the toilet tank to the toilet bowl. Over time, these bolts can become loose due to fluctuations in temperature and humidity, which can lead to leaks between the tank and bowl.
Start by visually inspecting the bolts that connect the tank to the toilet bowl. Look for any corrosion or buildup, which could indicate a loose connection. Try wiggling the tank back and forth gently - if you notice the tank moving independently of the bowl, the bolts likely need tightening.
Use an adjustable wrench or pliers to tighten the nuts on the tank bolts. Take care not to overtighten, as you can crack the porcelain. The bolts should be just tight enough so that the tank does not shift or rock back and forth.
If the bolts are so corroded that they cannot be adequately tightened, you may need to replace them. Shut off the water supply and flush the toilet, then disconnect the tank and install new bolts and washers.
Properly tightened tank bolts will help ensure there are no leaks between the tank and bowl. This simple step can go a long way towards resolving toilet leaks originating from a loose connection point.
Replace Tank Gasket
If the leak seems to be coming from the bottom of the tank, you likely need to replace the tank gasket. The tank gasket creates a watertight seal between the tank and the toilet bowl. Over time, this gasket can become cracked or damaged, allowing water to leak out.
To replace the tank gasket:
- Disconnect and remove the tank from the bowl. The tank is held in place with bolts on either side near the base. Loosen these bolts and lift the tank off the bowl.
- Clean the bottom of the tank and the top of the bowl where the gasket sits. Remove any old putty or gasket material using a plastic putty knife.
- Apply a thin bead of plumber's putty around the outlet opening on the bottom of the tank.
- Press the new gasket evenly into the putty. Make sure it fully seals around the tank outlet opening.
- Lower the tank back onto the bowl, aligning the bolt holes. Hand tighten the bolts evenly.
- Finally, finish tightening the bolts with a wrench, alternating back and forth between sides to evenly compress the gasket. Do not overtighten.
The new gasket should create a watertight seal between the tank and bowl. After reinstalling the tank, turn the water supply back on and test for any leaks. If the new gasket leaks, you may need to tighten the bolts further or reseat the gasket.
Turn Water Back On
After replacing any faulty tank components and ensuring all connections are tight, you can turn the water supply back on. Locate the shutoff valve that controls water flow to the toilet. It is usually found on the wall behind the toilet or under the tank. Turn the shutoff valve counterclockwise to open it and restore water flow.
Open the valve slowly and listen for any leaks. If you hear water running, close the valve and check connections again. Once fully open, the valve will allow water to refill the tank. Flush the toilet a few times and inspect closely for leaks. Look at all connections and around the base of the toilet. If there are no leaks, the repair is complete. Leaving the water on will allow you to monitor and ensure the repair was successful before putting the toilet back into normal use.
Test for Leaks
After reassembling the tank and turning the water supply back on, it's important to test for any remaining leaks. Here are the steps:
- Flush the toilet and allow the tank to refill completely.
- Closely inspect the tank and toilet base for any water dripping or pooling where it shouldn't be. Common leak points include:some text
- Where the tank bolts connect to the bottom of the tank
- Where the fill valve attaches to the tank
- Where the flapper valve seals against the flush valve seat
- Where the tank attaches to the toilet bowl
- If a leak is spotted, tighten connections or replace parts as needed. Small drips may stop on their own as parts settle into place.
- Repeat the flush and inspection process 2-3 times to confirm no leaks remain. If the toilet flushes and refills without any dripping or pooling water, the leak should be successfully repaired.
- Give it several hours and re-check for leaks occasionally. Small leaks may take time to become apparent. If everything remains dry, the repair is complete!
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