“Jiggle the handle!” The toilet bowl flushing mechanism is one of the most common toilet fix-it problems. This Fix-It Guide on toilet repair tells how a toilet works, what often goes wrong, how to identify a toilet problem, and what replacement parts you will need to fix it. It then gives simple step-by-step instructions for how to unclog a toilet, how to adjust or replace a toilet flush handle, how to adjust a toilet lift chain, how to clean a toilet valve seat, how to replace a toilet flapper valve, how to replace a toilet float ball, and how to replace a toilet flush mechanism. Some of these instructions also apply to bidet repair.
How Does a Toilet Work?
A toilet is a bathroom fixture that usually consists of a water-flushed bowl and seat. Two mechanisms operate simultaneously when a toilet is flushed: a flush valve and a fill (ball cock) valve. Tripping the flush handle raises the flush valve, releasing water from the tank into the bowl. The rushing water creates a siphoning action in the bowl that forces wastewater down the drain. As the tank empties, the lowering water level lowers a float that’s connected to the ball cock. As the float falls, it operates the fill valve inside the ball cock. Meanwhile, the flush valve closes itself after the water drains from the tank. With the fill valve open and the flush valve closed, the tank fills and the rising water lifts the float. When it reaches a preset level, the float closes the fill valve in the ball cock. At that point, the tank should be full and ready to flush again.
There are various versions of this mechanism, sometimes with their own brand name. However, essentially they all work about the same.
What Can Go Wrong with a Toilet?
A toilet can get plugged up and overflow or drain slowly. The handle can quit working effectively, and the flush mechanism or lift chain may need adjusting or replacing. The ball cock can malfunction. Leaks sometimes develop. A seat may need replacing. And a porcelain fixture can crack. All of these problems are fixable with basic tools and instructions.
How Can I Identify a Toilet Problem?
- If the toilet bowl overflows, use a plunger or auger (see below) to eliminate clogs.
- If the toilet does not flush, tighten or replace the defective handle (see below), adjust or replace the lift chain (see below), or replace the flush mechanism (see below). Jiggling the handle forces the lift chain or rod to re-seat the flush mechanism, telling you that something is awry.
- If the bowl drains sluggishly, remove the clog with a plunger or auger, or raise the water level in the tank (see below).
- If water runs continuously through the toilet, lower the water level in the tank (see below), adjust or replace a lift chain or wire (see below), repair or replace a worn flush valve (see below), clean or replace the valve seat assembly (see below).
- If water appears under the tank, tighten the tank hold-down bolts (see below), lower the water level in the tank, replace the float valve (see below), replace a malfunctioning ball cock, or tighten nuts on the water supply line, replace leaking supply line (see below). As a last resort, re-seat the toilet (see below).
- If the seat is cracked or unsightly, replace it (see below).
- If the bowl or tank is cracked or otherwise unacceptable, replace the entire toilet (see below).
What Do I Need for Toilet Repair?
Replacement parts are available at just about any hardware store. Special models may require a trip to a plumbing supply store. In either case, make sure you have model numbers, typically imprinted on the inside or underside of the tank unit. The tools you will need to fix a toilet (depending on the job) include these:
- Penetrating oil
- Rubber gloves
- Plastic container or bucket
- Bristle brush
- Nylon scrubbing pad
- Emery cloth
- Masking tape
What Are the Steps to Toilet Repair?
Make sure you turn off the water to the toilet before disassembling anything. The water shutoff is located on the wall below the tank and behind the seat. If you can’t find it, turn off the main water valve.
Unclog a toilet using a plunger:
- If the bowl is full or overflowing, put on rubber gloves and use a plastic container to bail out half the water. If the bowl is empty, add water to half full.
- Place the plunger firmly over the larger drain opening and move it up and down rapidly several times. If the water goes down the drain, you probably removed the blockage.
- Use the plunger again to be sure the water is running freely. Then pour in a pail of water and plunge one more time before flushing the toilet to refill the bowl.
- If the blockage remains after plunging, use an auger (see below).
Unclog a toilet using an auger:
- Determine the direction in which to guide the auger. Some toilets are rear draining and others are front draining.
- Feed the curved tip of the auger into the drain opening. Crank clockwise and push with moderate pressure until the auger tightens up, then crank in the other direction. When the auger tightens again, reverse the direction until the auger is as far in the drain as it will go.
- Pull the handle up and out to remove the auger. If it jams, push gently, then pull again. You may have to turn the handle as you pull up.
- Augering may either push the blockage through or pull gunk up into the bowl. After augering, remove any large pieces, wearing rubber gloves. Finish with a plunger to ensure that the drain runs freely.
Don’t get caught without a Plan B. Have plenty of rags, a sponge, and a pail nearby to catch water or clean up spills.
Adjust or replace a toilet flush handle:
Remove the cover from the toilet tank (the higher part at the back of the toilet). If the handle is loose, tighten the locknut with a wrench. If the nut won’t budge, apply penetrating oil and let it set before removing.
Unhook the chain from the trip lever and slide the trip lever, with the handle attached, through the hole in the tank.
Soak the handle threads in vinegar for an hour or so to remove mineral deposits, then scrub clean with an old toothbrush.
Reinstall the assembly, tighten the locknut and adjust the lift chain (see below).
Adjust a toilet lift chain:
- If the handle must be held down while the toilet is flushing, the chain may be too long. Shorten it by hooking the upper end through a different trip lever, or use long-nose pliers to open and remove some chain links. Alternately, replace the chain with a new one.
- Some flush assemblies have a lift wire instead of a chain. If the wire binds against its guide, flushing is impaired. Loosen the guide with a screwdriver, then adjust it so that the flush valve falls freely onto its seat.
Clean a toilet valve seat:
- Turn off the water supply and flush the toilet to drain the tank. Wearing rubber gloves, use a large sponge to mop out most of the remaining water. Disconnect the refill tube and slide the flapper valve off the overflow pipe.
- With emery cloth, gently scour inside the valve seat and along its rim, removing any debris. If the valve seat is badly pitted, replace it or install a rebuild kit that consists of a new flapper valve and valve seat, following the kit’s instructions.
- Reassemble the mechanism, then turn on the water supply and flush to check for leaks.
Replace a toilet float ball:
Note: Some toilets use proprietary float systems that must be replaced as a unit following manufacturer’s instructions.
- Grasp the float arm with locking pliers, and unscrew the float ball. If it will not come off, use pliers or a wrench to remove the float arm from the ball cock.
- Screw a new ball onto the float arm and screw the arm back onto the ball cock.
- Flush the toilet and adjust the water level as necessary (see below).
Replace a toilet flush mechanism:
- Shut off the water supply and flush the toilet. Remove the tank cover and place a container on the floor beneath the tank to catch water runoff. Wearing rubber gloves, sponge up any water remaining in the tank.
- With an adjustable wrench or adjustable pliers, unscrew the nut and disconnect the supply line where it enters the tank.
- Attach locking pliers to the nut at the base of the ball cock and loosen the locknut under the ball cock with an adjustable wrench or adjustable pliers. Unscrew the nut, and lift the ball cock up from the tank.
- Use a bristle brush or a nylon scrubbing pad to clean the opening in the tank where the ball cock was. Position the assembly in the tank with the cone-shaped washer of the new ball cock centered over the hole, and tighten the locknut snugly; do not over-tighten, or it may crack.
- Place the refill tube into the overflow pipe, reconnect the supply tube, and slowly turn on the water. Tighten the locknut slightly if the new hardware leaks.
- Adjust the water level in the tank as necessary (see below).
A toilet tank’s water level should be 1/2 to 1 inch below the top of the overflow pipe. A low water level results in an incomplete flush. If the level is too high, the water will drain into the overflow pipe and the toilet will run continuously. Here’s how to adjust the water level in the tank:
- To lower the water level: gently lift the float arm and bend it down slightly to keep the water level 1/2 to 1 inch below the top of the overflow pipes.
- To raise the water level: bend the float arm to raise the float ball, making sure that the ball does not rub the tank.
- To raise or lower a plastic float arm: turn the knob at the ball cock.
Tighten leaky toilet bolts or washers:
- If water is leaking from the bottom of the tank, first try tightening the tank hold-down bolts. Shut off the water and drain the tank. Use locking pliers or a wrench to keep the nut under the tank from spinning, and turn the screw inside the tank with a screwdriver. Turn the water back on and test.
- If that doesn’t work, shut off the water again, flush the tank, and mop any remaining water from the tank. Disconnect the supply line, unscrew the hold-down bolts, and remove the tank. Replace the gaskets and rubber washers, and reassemble.
Replace a toilet flapper valve:
- Unhook the refill tube and lift chain, then remove the flapper valve (see above).
and install a replacement valve seat following the manufacturer’s
instructions. If you cannot find a flapper valve that fits the seat, or
if the leak persists after replacing the flapper valve, install a
rebuild kit (see above).
Replace a toilet seat:
- Toilet seat bolts may be hidden under plastic caps. Pry open each cap. Hold each bolt with a screwdriver, and unscrew the nut with adjustable pliers. Some nuts have plastic “wings” that make pliers unnecessary.
- If the bolts are corroded, apply penetrating oil and allow it to stand for four to six hours and try again. If the bolts still will not budge, apply masking tape to the toilet rim to protect it, and then cut through them with a hacksaw.
- Replace the seat and bolts, then hand-tighten the nuts. Align the seat with the bowl and tighten the nuts one-quarter turn.
Re-seat or replace a toilet:
- If a toilet base leaks or you need to replace the toilet, shut off the water, drain the tank, disconnect the supply lines, and sponge water out of the bowl.
- Grasp the tank bolts with pliers and unscrew them, then lift off the tank.
- Remove the toilet seat.
- Remove the floor bolt caps and unscrew the nuts with an adjustable wrench. Straddling the toilet, rock it from side to side and carefully lift it off the bolts. Call your local recycler for information on how to dispose of the old toilet.
- Lay the toilet upside down on a protected surface; remove old wax, unless you’re installing a new toilet.
- Press a new wax ring over the opening of the old or new toilet, depending on which you will be installing.
- Position the toilet over the bolts and press it into place. Tighten the nuts. Reinstall the tank and the seat.
A flange-type plunger fits into the toilet drain and exerts more pressure than an old-style cup plunger.