Toilet Drip Sound: What Causes It and How To Fix It?

A toilet drip sound is usually not noticed until night because that is when the ambient noise of the house stops. But what could be causing it? And how do I fix it? Those are the questions we’ll be answering next.

Toilet Drip Sound

The toilet drip sound could be caused by an old flapper, a leaking pipe or fill-valve, a leaking seal due to calcium buildup, or a sweaty toilet. To fix these issues you’ll need to replace the damaged parts or install an anti-sweat valve in case you have a sweaty toilet.

Five Main Causes

1. The flapper in the toilet tank does not seal properly, preventing the float ball from rising to the top and stopping the water flow.
2. A cracked pipe behind the toilet is leaking.
3. The fill-valve is leaking.
4. There is a leaking seal from calcium buildup.
5. The back of the toilet is collecting condensation and dripping on the floor.

The Flapper Is Not Sealing

The flapper in the back of your toilet is a small rubber stopper preventing water from flowing into the toilet bowl. When you depress the flush mechanism on your toilet, it lifts the flapper allowing the water to pour into the toilet bowl (if your flapper is broken but won’t come off, see our post about it here). If the flapper does not seal completely, the water will continuously flow.

Add a few drops of food coloring to the water tank to test whether your flapper is sealing completely. Do not flush the toilet. You need to replace the flapper if you check the water in the bowl in an hour and it is colored.

Replacing the Flapper

• Shut off the water supply to the toilet by turning the shut-off valve clockwise.
• Flush the toilet to empty the tank.
• Remove the lid to the tank, and you should find it empty.
• The flapper is connected to a chain and in the bottom of the tank.
• Disconnect the flapper from the chain and hinges.
• Remove the old flapper.
• Remove the new flapper from the package.
• Connect the new flapper to the chain and hinges.
• Be sure the new flapper seals appropriately in the bottom of the toilet.
• Turn your water back on by turning the shut-off valve counter-clockwise.
• Allow the tank to fill while listening for leaks and watching the water level.
• The flapper is not seated tightly if you see the water level lowering while the tank is filling.
• Reseat the flapper.
• If you do not hear dripping, the water level is stationary, and the toilet bowl is full, congratulations! You have now fixed your toilet and got rid of the toilet drip sound.

The Pipe Is the Source

If you have determined that the dripping is coming from a cracked pipe, it may be time to replace some lines in your home. Also, if the pipes and valves have become misaligned with use over time, this is a relatively inexpensive fix. Finally, if you find that a cracked pipe is the culprit, hiring a plumber may be required to meet local codes.

How to Fix the Leaking Fill-Valve 

The fill-valve is usually located on the bottom left corner of the tank and connects to the pipe for the water supply to the toilet. Because it is always in a damp environment, the washers, nuts, and bolts can become rusted and brittle over time. However, it is an easy fix if it starts leaking.

• Shut off the water to the toilet.
• With pliers, turn the nut 1/8th turn clockwise.
• Turn the water back on.
• Let the water flow into the tank while listening and watching.
• If there is no leak, you are finished.
• If the leak continues, you must replace the nuts, bolts, and washers.
• Start by shutting off the water to the toilet to drain the tank.
• Take any hardware you remove with you to the hardware store.
• Purchase the same size that was initially attached to the valve.
• Replace the bolts and washers and reattach the valve.
• Turn the water back on.
• Tighten the bolts only until a water-tight seal is formed.
• If any parts are still not working, replace the whole valve following the above steps.

How to Remove Calcium Deposits 

Calcium deposits from hard water can rim seals, insides of tanks, and bowls with a scaled, crusty residue which causes leaks. Calcium deposits are alkaline, so acidic liquids like vinegar and lemon juice will help to dissolve and remove them. If the build-up returns quickly, the purchase of a water softener may be needed.

• Turn off the water in your tank or scoop out enough water to reach the deposits.
• Pour a small lemon juice or vinegar bottle into the toilet tank over the deposits.
• Allow it to sit overnight.
• The next day, use a stiff brush to scrub the deposits from all surfaces.
• Refill the tank with water and monitor for buildup.
• If the natural remedies do not work, try a chemical product like Lime Away.

Eliminating Moisture on the Toilet Tank

Condensation occurs when warm, moist air meets the porcelain surface of the toilet. There are two ways to remove condensation from the toilet tank. First, install a dehumidifier in the bathroom to remove moisture from the air. Second, install an anti-sweat valve. Installing an anti-sweat valve involves cutting pipes and soldering. Again, proceed with caution without the services of a plumber if you must.

To Install an Anti-sweat Valve (Consider Calling a Plumber)

An anti-sweat valve adds a little warm water to the tank raising the temperature of the water in the bowl to prevent the accumulation of sweat on the toilet. An adjustable valve is recommended and is available at the hardware store.

Preparation for the Valve

• Begin by shutting off the water to the main supply to the house.
• Drain all hot and cold lines in the house by flushing all toilets and opening all faucets.
• Use brass connectors to avoid scorching inside of pipes.
• Loosely thread a ⅝ by ⅝ in the adapter into each of the three valve ports. Then, hold the valve so the lower inlet is even with the cold water pipe.
• Note and mark where the valve intersects with the horizontal cold water pipe.
• Next, consider hiring a plumber before you do the next step.
• Use a hacksaw to cut out the pipe section.
• Now, solder a 90-degree, L-shaped fitting to the pipe coming from the toilet. Next, extend it with a 6-inch long piece of ½-inch diameter pipe.
• With the cold water pipe now ready, locate the closest hot water pipe and cut out a section to accept the new copper T-fitting.
• Splice the T-fitting into the line.
• Assemble a short, vertical riser with a 90-degree L-fitting and short stub.
• Aim the stub to where the valve will be attached to the cold water pipe that goes into the tank.
• Solder the T- and L-connections.

Install the Valve

• Lightly coat the three male adapters of the valve with a joint compound.
• Thread the adapters into the ports and tighten.
• Slide a nut and compression ring into each pipe and then insert them into adapters.
• Use pipe compound on each ring and thread the nuts into the adapters while tightening.
• Turn the water back on and check the work you completed for leaks.
• If there is a leak, tighten the bolts with a wrench enough to stop the leak.

Final Thoughts

Most of the above repairs for toilet drip soundheard during quiet times are easy and low-cost do-it-yourself fixes. However, installing an anti-sweat valve involves soldering and cutting pipes, so hiring a plumber is highly recommended. In addition, many local plumbing codes need a licensed professional to cut and solder any pipes in a house.

So if your problem is related to the anti-sweat valve, act with caution and hire a professional. Check with friends, neighbors, and your local builder’s association for recommendations. Investigate reviews but be mindful that they can be inaccurate or placed by the tradesman. Be flexible when making the appointment. Have the work area clean and barrier-free when the tradesman arrives.