Toilets are relatively simple mechanisms — they contain few parts, no motors and require no electricity to run. In fact, their operation hasn't changed much in the past several hundred years. However, despite their seeming simplicity, the operation of toilets continues to mystify many, perhaps because most of their working parts are concealed inside a tank.
In this article, we'll introduce all parts of a toilet, explain how they work and teach you how to troubleshoot and fix a toilet that keeps running.
A Tour of Your Commode
Take off your toilet's lid, set it aside and look closely at all the components in your tank. If you own a normal flush toilet — which is the type owned by 95 percent of homeowners — the components will be similar to these:
1. Flush Rod and Handle
These two components work together to start the flush. You'll notice that the handle is connected to a rod attached to a wire or chain. These handles sometimes become loose and can usually be easily fixed by tightening the metal or plastic mounting nut found in the tank. It should be noted that this mounting nut is not threaded in the usual way, and you must turn it counterclockwise to tighten.
2. Lift Chain or Wire
The rod is attached to a chain or wire that descends to the tank's bottom. The lift chain or wire opens the toilet's flush valve and allows the contained water to exit the tank and enter the bowl. It is not uncommon for lift chains to become broken or tangled, so if you're experiencing flushing problems, your lift chain may be the cause.
Your lift chain is connected to a flapper made of rubber, which covers up the opening of the flush valve. If your toilet is particularly old, it may instead have a tank ball. It might be difficult to clearly examine the flapper if your tank is full, but once you flush the toilet and observe the flapper in action, how it works will become clear. The handle and lift chain lift the flapper off the flush valve, at which point the water in your tank rushes into the bowl. Eventually, flappers will become misaligned or just wear out, leading to water leaking into the bowl after the toilet has been flushed. Faulty flappers are a common cause of constantly running toilets.
4. Flush Valve
The flush valve is the metal or plastic component found at the tank's bottom that forms the opening that the water travels through when the toilet is flushed.
5. Overflow Tube
The overflow tube is typically attached to the flush valve and serves to prevent water from overflowing in the tank if the water supply doesn't shut off. If an overflow occurs, the excess water spills into the overflow tube and travels down to the bowl.
6. Shutoff Valve
This component is located on a pipe outside your tank that supplies the water. In most cases, this valve is to the left of your toilet and underneath the tank. This valve allows the water to be shut off when repairs need to be made. Some toilets do not have these valves, but they are highly recommended. These valves tend to fail at a certain point, and replacing them is a common project for DIYers.
7. Supply Tube
This tube is made of plastic, steel mesh or vinyl and runs from your shutoff valve to the water supply tailpiece found on the tank's underside. While these tubes rarely cause any trouble, they have been known to fail if the connections become loose.
8. Water Supply Valve
The water supply valve is usually found on your tank's left side and is also known as a ballcock. This vertical assembly is your toilet system's main component, as it is what allows fresh water to enter the tank after flushing and shuts off when the water in the tank reaches the right level. The water supply valve is a source of many toilet issues.
9. Float Cup
The float cup serves to detect when the water in the tank has reached the desired level, at which point it will cut off the supply of water. If your toilet is older, you may instead have a floating ball, which is connected to a pivot arm that runs to the water supply valve. Newer types of toilets usually have a float cup, which is connected to the supply valve's vertical shaft. You can adjust your tank's water level by adjusting this float device.
10. Refill Tube
The refill tube is a small component that runs from your water supply valve and is clipped to the top part of your overflow tube. It serves to send small amounts of water into the bowl while the tank is being refilled. This replenishes the level of standing water in your toilet bowl. Standing water in your bowl is absolutely essential, as it provides protection from sewer gases.
11. Toilet Bowl
The toilet bowl is, of course, one of the parts we always see. One part we cannot see, however, is a curved trap inside the bowl, which functions like the trap on a sink drain. These traps exist to hold water and keep sewer gases from entering your home. The water that you see resting in your toilet bowl is actually part of the drain trap of your toilet. The drain trap is the source of the most common toilet problem of all — clogging.
12. Wax Seal
Hidden underneath the toilet, there's a wax ring sealing the attachment of the floor's drain opening and the toilet's bottom. This seal creates a water-tight and airtight connection between the sewer line and the toilet. If the wax seal fails, water may seep out by the toilet's base when you flush. Replacing wax rings can be messy, but it will need to be done at some point.
How Your Toilet Flushes
You can get a good grasp of how your toilet works and the problems that may occur by looking at the inside of your tank while you flush it. Here is what happens after you pull the handle:
- Water exits the tank. When you push the handle, it operates the lift chain, which pulls the toilet flapper up, allowing water to escape through the flush valve and go into the bowl.
- The toilet bowl water drains. The water standing in the toilet bowl and the waste it contains are siphoned into the integrated trap and then into the drain system.
- Freshwater enters the tank. When the water escapes through the flush valve, the float cup drops down, which causes the supply valve to be opened, and freshwater begins to enter. The majority of this water is used to refill the tank, with the remainder going into the toilet bowl via the refill and overflow tubes.
- The water supply shuts off. When the float cup on top of the water reaches the required height, the water supply is shut off. Your toilet is now prepared for its next flush.
Why Does My Toilet Keep Running?
By now, you should have a general understanding of the parts that comprise your toilet system and how they interact. Now we'll cover the many ways to troubleshoot and solve one of the most common toilet problems — running. Below are four troubleshooting tips:
1. See If You Have a Malfunctioning Chain or Flapper
As mentioned above, the flapper refers to the rubber or plastic cap that prevents water from escaping from your tank. With time, flappers may become hard, leading to an imperfect seal. If you find that your tank isn't refilling or holding water, the likely cause is a bad flapper. Follow these steps to troubleshoot your toilet flapper:
- Examine the consistency of the flapper. Toilet flappers often become brittle with age and eventually fail to create a sufficient seal. Make sure your flapper still feels soft and can hold back the water in the tank.
- Examine the chain. Check to see if the chain attached to the flapper is caught on something. If the chain is excessively long, take out some of the excess so that tangles won't occur. If it's rusting, it should be replaced.
- Look for jams. Sometimes flappers get pinched around the hinges, which can prevent a complete seal. Inspect both sides of your flapper for jams.
- Check the alignment. Flappers can become dislodged as well, which can cause leaks. Ensure that the flapper is sealed directly above your drain.
- Check for mineral deposits. Mineral deposits can accumulate on your flapper, preventing it from forming a proper seal. If you notice any deposits, clean it by soaking it in vinegar for half an hour. Then get a brush and scrub the flapper to dislodge dirt and buildup. You can alternatively clean the flapper by wiping it down with a rag with shampoo, which will clean it and give it more elasticity. Once it's clean, place it back over the flush valve and connect the hooks on the sides to the overflow tube's pins.
2. Adjust Your Water Level
The overflow tube in your tank prevents it from overfilling and flooding the bathroom. However, if the float cup is positioned too high, some water will enter your overflow tube and go into your bowl, which will result in your fill valve periodically turning on to top up your tank.
Here's how to go about adjusting your water level:
- Lower your fill valve's float setting. Your valve may come with a rod and tiny clip that you must squeeze to slide down or up along the rod. If you want to lower your water level, slide your clip down. If you have an older toilet with a longer rod and tank ball, bend the rod carefully so that the ball can go a bit deeper in your tank.
- Flush your toilet. Allow it to fill back up and stop.
- Check the level of the water. The level should be roughly 0.5 to 1 inch lower than the top of your overflow tube.
- Continue to adjust the float. If needed, continue adjusting the float and flushing until the tank fills up to the recommended level.
3. See If Your Float Is Water-Logged
Floats that have become water-logged can also cause toilet running. If there is water trapped in the float, the float will sit in the water at a lower level than desired, leaving the float valve open. To check the float, unscrew it and shake it. If you hear water sloshing around inside, replace it.
4. Replace Your Fill Valve
The water flowing into your tank is controlled by the fill valve. If broken, it may no longer shut off the supply or just do so inconsistently. A common warning sign of a malfunctioning fill valve is a submerged float valve. Fill valves are cheap and simple to replace, so if yours stops working, we recommend that you just buy a new one rather than try to fix it.
Here is how to perform a fill valve replacement:
- Close your shutoff valve. Turn off the supply of water by turning the knob to the shutoff valve, which is attached to the pipe that leads to your toilet. Then, take off the lid of your tank and give your toilet a flush to empty it.
- Remove the water supply hose. Put a plastic bucket or bin underneath the supply hose and then disconnect it from your fill valve located underneath the tank.
- Take out the broken fill valve. The broken fill valve can be removed by unscrewing your locking nut found under the water supply shank and pulling out the whole valve assembly. Any water left in the tank will go into the bucket or bin that you've placed under the fill valve.
- Put in the new fill valve. Place the new fill valve in your tank and adjust its height to fit that of your tank, making sure to follow the directions of the manufacturer. Find the valve's threaded end and insert it into the hole found in the tank. Then, secure the valve using your locking nut, and tighten it with your hand. Then, to make sure the seal is watertight, turn the locking nut further using pliers. Make sure to not over-tighten the nut.
- Attach your supply hose. Connect your supply hose to your fill valve, then use pliers to tighten it fairly snugly. Then, clip your hose to the top part of your overflow tube, and make sure that the hose points into your tube. The majority of valves come with an angle adapter or clip to make sure the tube is positioned at the correct angle. When positioning the tube, make sure it stays above the water line — otherwise, the tank will be constantly refilling.
Turn the water back on. Go to your shutoff valve, turn the water on and allow your tank to refill. If necessary, adjust your water level to the level specified by your manufacturer.
While the above troubleshooting procedures are all relatively simple, keeping the following in mind will help you avoid problems:
- Follow codes. Inform yourself of any codes that may apply to these jobs and follow them.
- Don't overtighten. Bolts, nuts and any other connectors should be tightened snugly, but overtightening metal parts may cause the toilet to crack, and overtightening plastic components could damage the plastic.
- Use care with fasteners and connectors. When turning fasteners or connectors, be careful not to damage them. Applying some tape to a wrench or the jaws of your pliers can help to protect metal fasteners' finish.
- Handle the lid with care. When you remove the lid of the tank, do so with care and put it a place where it won't likely be damaged.
- Get the right replacement parts. When purchasing replacements for components of your toilet, make sure that they fit. For instance, flappers are available in different types (solid-frame and flexible) and different sizes (2-inch and 3-inch) so make sure that the specifications of your new flapper match those of the existing one. To help with this, we recommend bringing existing parts along with you to the store.
When to Call a Professional
If you've tried all of the above troubleshooting tips and your toilet is still running, we recommend calling a professional.
Here are some other instances where calling a professional is recommended:
1. You Can't Easily Unclog Your Toilet
As you know, most toilet clogs can be quickly resolved with a plunger. But if you have no luck after a few plunges, stop and contact a plumber, because continuing to plunge could actually damage your toilet and even the piping. A plumbing professional should be there promptly to unclog your toilet, figure out what caused the issue and keep it from occurring again.
Plumbers carry specialized tools such as cameras that go deep into pipes and look for things that might be causing long-term issues. Potential issues include build-up of grease, accumulation of hair, septic tank problems and roots interfering with underground systems.
2. Your Toilet Backs up by Itself
If your toilet starts to overflow for no apparent reason, there is a good chance that the main drain pipe or sewer line is clogged. These types of clogs cause water to travel up into your toilet bowl whenever anything is running, including sinks, showers and dishwashers.
If your toilet overflows by itself, immediately refrain from using water throughout the house and call a professional plumber. They will help determine the issue and show you how it will be fixed. This sometimes involves cleaning pipes and other times a thorough examination of your entire home.
If your home has its own septic system, backflow can occur if the tank fills up. This situation can be quite smelly and potentially dangerous, as occupants can be exposed to various types of wastewater. If this occurs, it is critical that you contact a plumber right away. Regularly cleaning out your septic tank will help avoid this unpleasant situation.
3. Your Hear Gurgling
If you notice that your toilet gurgles when you're not using it, this means it is searching for air and a backup is imminent. If you notice gurgling while running the dishwasher or showering, turn the water off immediately to keep the system from backing up into your home.
4. Your Water Pressure Is Low
If your toilet takes a long time to flush, this can be a sign of low water pressure, which is caused by leaks, clogs, pipes that are incorrectly sized and various other problems. Regardless of the cause, a professional plumber can fix it in a jiffy.
5. Water Is Pooling Around Your Toilet's Base
If you notice water pooling at the base of the toilet, this means that the toilet is loose. Refrain from using it and call a plumber right away.
Contact Mr. Rooter of Greater Syracuse
If you're a homeowner or business owner in Greater Syracuse, N.Y., and are experiencing plumbing issues of any kind, Mr. Rooter of Greater Syracuse will promptly come to your rescue. Our certified plumbers have the skills and tools to deal with all kinds of plumbing-related emergencies and are available all hours of the day, every day of the year. You can reach us by filling out our contact form or by calling (315) 472-1203