Toilet Won’t Flush? 8 Common Causes and How to Fix Each One

You press the handle and nothing happens. Or the handle feels loose and limp. Or the water swirls half way and gives up. A toilet that will not flush is one of the most stressful small emergencies in a home because you cannot put it off. The good news is that the cause is usually simple and cheap to fix. A bent chain or a worn flapper or a closed valve accounts for a large share of cases and you can fix most of them in minutes with no special tools.

This guide explains why your toilet won’t flush and how to find the cause fast. You will learn the eight most common problems and the exact repair for each one including what to do when the toilet will not flush but is not clogged. You will also see what a plumber charges and the signs that a problem is bigger than the tank.

When the clog sits deep in the main line a plumber may suggest hydro jetting. Our hydro jetting cost guide shows typical prices.

How a Toilet Flushes

Knowing how a toilet works makes troubleshooting much easier. When you push the handle a lever inside the tank lifts a chain that raises a rubber flapper. Water rushes from the tank into the bowl and the force pushes waste through the drain. The flapper then drops back down and the tank refills through the fill valve.

Everything in that chain has to work for the toilet to flush. A weak link anywhere along the way gives you a toilet that does nothing or flushes weakly. That is why the first step is to figure out where the process stops.

Quick Checks Before You Dig Into the Tank

Start with the fastest tests.

• Lift the tank lid and press the handle. Watch what moves. If the handle moves but nothing in the tank reacts the problem is the handle or the chain.
• Check the tank water level. An almost empty tank means water is not refilling. A full tank with a toilet that will not flush often points to the flapper or a clog.
• Look at the shutoff valve behind the toilet. It should be fully open.
• Test another faucet. If a sink in the house has no water the problem is the supply and not the toilet.
• Listen after the flush attempt. Gurgling can point to a clog or a venting problem.

These checks usually point you to one of the causes below.

Cause 1: The Shutoff Valve Is Partly Closed

The supply valve behind the toilet can get bumped while cleaning or after a repair. When it is partly closed the tank refills slowly or not at all and you get a weak or empty flush.

The fix: Turn the valve handle counterclockwise until it is fully open. Wait a minute or two for the tank to refill and then flush. If you still hear little or no water entering the tank look at the next causes.

Cause 2: The Handle or Lift Arm Is Loose or Broken

If the handle feels loose or spins freely without lifting anything the connection inside the tank has failed. The handle may be loose on its mounting nut or the lever arm may have snapped.

The fix: Remove the lid and look at the lever arm. Tighten the mounting nut (it often turns the opposite way from what you expect since it has reverse threads on many models). If the arm is broken buy a replacement handle for your toilet. This is a quick and inexpensive repair.

Cause 3: The Lift Chain Is Too Loose or Too Tight

The chain connects the handle lever to the flapper. If it has too much slack the lever pulls the slack and lifts the flapper only a little or not at all. That gives you a weak flush or no flush. If the chain is too tight the flapper cannot seat and the toilet can run constantly.

The fix: Move the chain hook to a shorter link so that there is very little slack when the flapper sits closed. Trim excess chain if needed but leave a little play so the flapper can close fully. Flush and check that the flapper lifts all the way. If the chain has come off the lever or snapped reattach it or replace it.

Cause 4: A Damaged or Worn Flapper

The flapper is the rubber seal at the bottom of the tank that lets water into the bowl. Over time it warps or hardens or gets coated with mineral deposits. A flapper that does not lift or seal properly causes weak flushes or a toilet that only flushes when you hold the handle down. If the tank empties slowly when the toilet is not in use you may also hear it running.

The fix: Turn off the water and flush to empty the tank. Unhook the chain and slide the old flapper off its pegs or ears. Install a flapper made for your model (bring the old one to the store to match). Reconnect the chain with a little slack and turn the water back on. A new flapper typically costs under $10 and is an easy DIY job.

Cause 5: Low Water Level in the Tank

A toilet needs enough water in the tank to flush with force. If the level is too low the flush is weak and may not clear the bowl. The usual culprits are a faulty fill valve or a float set too low.

The fix: Look for the water line marked inside the tank or check that the water sits about an inch below the top of the overflow tube. Adjust the float (a ball or a cup that rides on the fill valve) so that the tank fills to the right level. If the fill valve is cracked or stuck replace it. A new fill valve is an inexpensive part and a common DIY repair.

Cause 6: A Clog in the Drain or Trap

A clog is the most common reason a toilet will not flush or drains slowly. Heavy toilet paper or an object that does not belong can block the trap. You may see the bowl fill up and drain very slowly after a flush.

The fix: Use a plunger first. If you do not have one see our guide on how to unclog a toilet without a plunger. Hot water and dish soap and a toilet auger solve most clogs. Avoid harsh chemical drain cleaners since they can damage the toilet and the pipes.

Cause 7: Clogged Rim Jets

Under the rim of the bowl are small holes called rim jets that release water during the flush. Mineral deposits from hard water or bacteria can block them. When that happens the bowl gets less water during the flush and the toilet flushes weakly or incompletely even though the drain itself is clear.

The fix: Use a small mirror to look under the rim and check whether the holes are caked. Clean each hole with a bent wire such as a straightened hanger or a small brush. You can also pour white vinegar into the overflow tube (the tall pipe in the tank) to soak the passages and then flush. Wear gloves and protect your eyes while you work under the rim.

Cause 8: A Blocked Vent or a Deeper Drain Problem

Plumbing vents let air into the drain so water can flow smoothly. A blocked vent pipe on the roof or a partial blockage in the main line can cause slow flushes and gurgling and repeated clogs across the house. If other drains are slow or gurgle when you flush this may be the cause.

The fix: This is usually a job for a professional. A plumber can inspect the vent and the main line with a camera and clear any blockage. If the toilet keeps stalling for no clear reason a plumber should also check whether the drain has enough downward slope.

Toilet Won’t Flush but Not Clogged: What Else Could It Be?

If the bowl drains normally but the toilet will not flush properly the problem is almost always inside the tank or at the supply. Work through this order:

• Handle: Does it lift the lever and the chain?
• Chain: Is there too much slack or has it come off?
• Flapper: Is it worn and does it lift fully?
• Water level: Is the tank filling to the right height?
• Shutoff valve: Is it fully open?
• Rim jets: Are they blocked with deposits?

Running through these six points finds the cause in most cases. Fix the first problem you find and test the flush before moving on.

Why Does the Toilet Only Flush When I Hold the Handle Down?

A toilet that flushes only while you hold the handle is almost always telling you the flapper is not staying open long enough. The cause is usually a flapper that is worn or a chain that is too short or tangled. Adjust the chain so the flapper has just enough slack to lift fully and drop back. If that does not help replace the flapper.

Why Does the Toilet Flush Weakly?

A weak flush can come from a low tank water level or a partly closed supply valve or clogged rim jets or a partial clog. Check the water level and the valve first. Then clean the rim jets and test the drain for a partial blockage. If an older low flow toilet has always flushed weakly you may want to consider an upgrade.

What If There Is No Water in the Tank?

If the tank is empty and will not refill check these in order:

• The shutoff valve. Make sure it is open.
• The fill valve. Listen for water entering. A silent fill valve may be stuck or clogged with debris.
• Other faucets in the house. If none have water you may have a supply outage or a shutoff at the main. Call your water provider.

How Much Does It Cost to Fix a Toilet That Won’t Flush?

The cost depends on the cause.

• Chain or handle repair: A few dollars for a new chain or handle.
• Flapper replacement: Typically under $10 for the part.
• Fill valve replacement: An inexpensive part for DIY. A plumber may charge more for labor.
• Clearing a clog: One source cites an average of $200 to $700 to unclog a toilet with higher costs when the drain line is the problem.
• Vent or main line work: Often the most expensive and priced by the job.

If you pay a plumber labor usually dominates the bill. For a broader picture of what repairs cost see our plumbing repair cost guide.

When to Call a Plumber

Most flushing problems are a DIY fix. Call a professional if:

• The toilet still will not flush after you check the tank parts. The problem may be deeper in the plumbing.
• Several drains in the house are slow or gurgling. This often points to the main line or the vent.
• The toilet clogs repeatedly. A repeat clog suggests a bigger issue.
• Water leaks around the base of the toilet. This may need a new wax ring.
• You are not comfortable working inside the tank. There is no shame in calling a pro.

If your toilet is old and keeps giving you trouble a replacement may make sense as part of a bathroom project. Our bathroom remodel cost guide covers what bathroom upgrades cost and our DIY home improvement guide can help you decide which jobs to take on yourself.

How to Keep Your Toilet Flushing Properly

A few habits prevent most flush problems:

• Check the flapper and chain once a year. Replace the flapper every few years or when it looks warped.
• Clean the rim jets now and then. A quick vinegar soak prevents mineral buildup.
• Do not flush wipes or paper towels. They cause clogs even if the package says flushable.
• Use a moderate amount of toilet paper. Flush twice for a large load.
• Learn where the shutoff valve is. You can stop an overflow in seconds.
• Fix small problems early. A toilet that runs or flushes weakly will not improve by itself.

Frequently Asked Questions About a Toilet That Won’t Flush

Why won’t my toilet flush?

The most common reasons are a partly closed shutoff valve and a loose chain and a worn flapper and low tank water and a clog. Check the handle and chain and flapper and water level in that order.

Why won’t my toilet flush but it is not clogged?

If the drain is clear the problem is usually in the tank. Check for a loose or broken handle and a chain with too much slack and a worn flapper and a low water level. Clogged rim jets and a partly closed shutoff valve can also reduce the flush.

How do I fix a toilet that won’t flush?

Open the tank and see what happens when you press the handle. Tighten or replace the handle and adjust the chain and replace a worn flapper and set the water to the correct level. If the bowl drains slowly clear the clog.

Why does my toilet only flush when I hold the handle down?

The flapper is probably dropping too early. A worn flapper or a chain that is too short or tangled is the usual cause. Adjust the chain or replace the flapper.

Why is my toilet flushing weakly?

Low water in the tank or a clog or clogged rim jets are common causes. Check the water level and the shutoff valve and then clean the rim jets.

How much does it cost to fix a toilet that won’t flush?

A new flapper costs under $10 and a new chain or handle costs a few dollars. A plumber may charge $200 to $700 on average to clear a toilet clog with higher prices for drain line work.

Can I fix a toilet that won’t flush myself?

Yes in most cases. Handle and chain and flapper and water level problems are simple DIY repairs. Call a plumber for blocked vents and main line problems.

Final Thoughts on a Toilet That Won’t Flush

When a toilet won’t flush stay calm and check the simple things first. Open the shutoff valve and look at the handle and chain and flapper and water level. Those four checks fix most flushing problems for a few dollars and a few minutes.

If the tank parts look fine and the bowl still does not flush clear the drain and clean the rim jets. If several fixtures act up or the toilet keeps clogging call a plumber to look at the vent and the main line. A little attention now saves you from a bigger repair later.