Troubleshooting Toilets


The toilet is one plumbing fixture that everyone needs to work well. The toilet must fill, the toilet must flush, and if everything is in proper working order, the toilet will do these things with minimal noise and hassle. Of course, there are many times when the plumbing of a toilet does not go with the flow, so to speak, and requires a little toilet TLC.

Any gravity toilet will include a fill valve, which controls the flow of fresh water into the toilet tank. It is attached to a water-supply connector through the bottom of the tank. Two types of fill valves are in use today. One is the traditional float ball (also called a ballcock), and the other is the float cup type.

The flush valve controls the discharge of tank water into the bowl. This valve consists of a flapper (also called “stopper” or “tank ball”), that aligns over the drain and is attached to the overflow pipe.

Above: Diagram of Ballcock-type fill valve

The overflow pipe, which is often attached to the flush valve, supplies refill water to the bowl as well as preventing overflow of the tank.

The tank lever is comprised of a lever arm and a flush handle. When the flush handle is pressed, the lever inside the toilet tank lifts the flapper allowing the water to flow into the bowl.

While fairly simple in design, over time these toilet components can wear out and corrode. This can lead to problems with flushing and refilling the tank. Here’s a quick overview of some typical toilet problems and what you can do to solve them.

Above: Diagram of Float cup-type fill valve

Trickling Toilet

You may hear fresh water trickling in the tank when you haven’t flushed the toilet. To remedy this, first look down the inside of the overflow pipe. If water is running from the refill tube into the overflow pipe, then check the      fill valve.

For ballcock-type fill valves, the float ball rod is at the top of the tank, with a hollow plastic or copper ball on the right-hand end. If it’s bent in any direction, then carefully straighten it by hand. If the rod is straight and the float ball does not lightly rest on the tank’s water surface, it probably has a leak and requires replacement.

Also, the tank’s water level may be set too high. Lower the water level with the adjustment clip. You’ll find the clip on the ballcock link. Just squeeze the two sides of the clip and push it down the link to adjust the water. Float cup-type fill valves also feature a water-level adjustment clip on the cup mechanism.

Next, remove any buildup under the fill valve seal. Buildup can be easily removed in a couple of minutes. Just shut off the water and remove the top of the ballcock or float cup valve. Cover the opening with an upside-down glass. Turn the water on and off a few times, and any buildup should be flushed by the water stream. Turn the top over and rinse it under a faucet. Reattach the top of the valve and make sure the water is turned on.

Then look for corrosion or sticking in the lever. Unfortunately, there is no quick solution for corrosion. If you see rust, you’ll need to replace the entire mechanism.

If you’ve tried everything mentioned above and the water continues to run through the refill tube after working through, then the fill valve seal is probably defective and requires replacement.

However, let’s say you hear the water running in the tank, and upon inspection you find that water is not running from the refill tube into the overflow pipe. In this case, check the placement of the refill tube. The refill tube is the small vinyl tube that stretches from the fill valve on the left of the tank to the hollow pipe on the right. If the refill tube is inside the overflow pipe, raise the end until it is just above the top of the overflow pipe. The adapter should hook to the top of the pipe.

Next, check the float ball rod and float, following the instructions above. And then check the flapper.

The flapper functions as the gate that allows the tank’s accumulated water to rush into the bowl when flushed. If the flapper is dirty, just clean it with a rag to remove any grime or buildup. If the stopper is worn out, it can sit askew and not seal properly. So if it’s damaged, warped or corroded, replace it along with the valve seat. A warped or corroded flapper is often the symptom of high chlorine levels in the water. If this is the case, remove any chlorine cleaning products from the tank and install a new flapper or ball specifically designed for use with highly chlorinated city water supplies.

If none of the above troubleshooting tips work, then the overflow pipe and/or flush valve are probably corroded or leaking and need to be replaced.

Toilet Will Not Flush

If the toilet just won’t flush, check the water supply’s shut-off valve at the wall. The toilet’s water might be turned off or partially shut. Just turn the water supply valve counterclockwise to completely open it. Then, tighten the top of the ballcock or float cup. Make sure it locks tightly into place.

In some cases, the chain between the toilet lever and the flapper may have detached. If this is the case, the chain can easily be reattached or replaced.

Tank Fills Slowly

If the toilet tank fills slowly—or not at all—clean the fill valve interior. Shut off the water at the wall connection, lift the float arm and twist the ballcock or float cup top until it unlocks.

Use a coat hanger or other stiff wire to gently scrape out the inside of the fill valve. Hold an upside-down glass over the valve opening and turn the water on and off three or four times. This will flush any deposits from the inside. Rinse the ballcock top under a faucet to clean the seal, and then replace the top, turning it clockwise until it locks.

Turn on the water supply completely to see if this solved the problem. If the tank still doesn’t fill properly, replace the pipe that runs from the wall to the toilet. Braided stainless steel toilet connectors are preferred.

Noisy Toilet When the Tank Fills

If the toilet is too loud when refilling, make sure the shut-off valve at the wall is completely open. Then inspect the angle adapter. The angle adapter is typically a rigid, plastic elbow that directs water from the end of the refill tube into the overflow pipe.The angle adapter may be completely vertical. If so, tweak the adapter slightly toward the inside wall of the overflow pipe. Flush the toilet and make sure the fresh water hits the pipe wall a couple of inches from the top before running to the bottom of the tank.

If this didn’t do the trick, then the fill valve is probably broken or malfunctioning. You’ll need to replace it.

Loud, Banging Pipes

If the pipes bang after flushing the toilet, a problem sometimes called “water hammer,” you may need to aerate your home’s drainage plumbing system. The problem occurs when there is not enough air in the right places in the water line. Start aerating by turning off the water supply to the entire home. Open all plumbing fixtures, including the faucet, shower, tub and exterior valves, and flush every toilet. Allow the system to aerate for about 15 minutes.

Then turn on the home water supply and turn off all the faucets you opened earlier. Remove the fill valve top and hold an upside-down glass over the exposed pipe. Turn the toilet’s water supply on and off three or four times until any debris is flushed. Rinse the top seal under a faucet and replace the top to the valve.

Incomplete Flush

If the toilet doesn’t totally flush or it doesn’t fill properly then turn your attention away from the tank and look to the bowl. The holes under the bowl’s rim could be limiting the amount of water entering the bowl. Use a coat hanger or stiff wire to clean each one, clearing any obstructions from the holes. Then flush. Next, tighten the flush handle. Tighten the set screw attaching the handle, but allow some play up and down. If the handle or set screw is corroded, replace the entire mechanism.

Also, make sure the flapper closes only after the tank is empty. Adjust the chain, allowing 1/2 inch of slack. If necessary, replace the flapper according the manufacturer’s instructions.

Toilet Jam (Overflow)

Sometimes a toilet can become filled with too much paper or with some other obstructing material. The first line of defense in an emergency of this type is to have a Plumber’s Force Cup at hand. Place the force cup at the drain exit of the toilet bowel and pump it up and down with the force cup handle. This will usually free the blockage and start the toilet draining process.

In more severe cases, or when the blockage is in the drain line below the toilet, use a Plumber’s Snake to free the obstruction.

Hot Product

Mule garage fan
MULE Garage Fan

The MULE Garage Fan is a high-velocity, 18-inch fan built for garages, workspaces, fitness centers, warehouse spaces and more – and powerfully designed to keep any space cool and comfortable, even during the hottest months. Designed with unmatched versatility and portability, the MULE Garage Fan features a universal mounting system and eight-foot standard power cord, […]