It’s common to see toilet tanks not filling up instantly after flushing nowadays. It’s because of the faulty fill valve, bad float or cup, leaks and damages in the tank, or low water pressure in most homes.
However, there can be other issues behind this and one needs to troubleshoot to find out the real problem.
Generally speaking, your toilet tank should refill itself up to a few inches below the overflow tube after every flush.
This usually takes between 10 to 15 minutes, depending on water pressure and the size of the tank.
But if the toilet tank stops refilling itself with water suddenly, then something is wrong with the system.
There are several different reasons why this might happen. This post will highlight all these reasons as well as give practical solutions to fix your no-fill toilet tank. Read on.
Why a Toilet Tank Won’t Refill After Flushing?
Here are the major reasons why your toilet tank won’t fill back after flushing:
1. Faulty Fill Valve
A faulty fill valve is the most common reason why your toilet tank would stop refilling itself.
The fill valve controls when to fill and when to stop filling the toilet tank. But if the valve becomes faulty, it will no longer let the toilet tank refill.
If you’ve been using the toilet tank for many years, chances are that the useful parts of the fill valve would have been worn out and need replacement. Or there is a buildup of debris in the tube assembly, restricting or slowing down the normal flow of water.
In rare cases, the toilet fill valve may be incorrectly installed, resulting in no or limited water flow into the tank.
2. Bad Float Ball or Cup
A float ball is found in old toilet models while a float cup/cylinder is found in newer toilet models.
Both of them are designed with a float arm that stops the inflow of water once the water in the tank reaches the optimal height.
If the float ball or cup is not adjusted correctly, it will affect the inflow of water into the tank.
This is another common reason why toilet tanks don’t fill up. For instance, if the float cup/ball is set too low, too little water will be allowed into the tank. The float ball/cup and float arm can also wear out, causing the system to malfunction.
3. Low Water Pressure
Another likely reason why your tank won’t refill is low water pressure. Low water pressure will cause water to trickle into the tank or shut the water off before filling the tank.
This will also cause your toilet to take a long time to refill the tank. However, if the water pressure is too low, it can completely stop the flow of water into the toilet tank.
You can check your home’s water pressure using a water pressure gauge. The standard water pressure is between 40 and 60 psi. Anything below this is considered low water pressure.
There are several ways to improve your home’s water pressure. This includes using a water pressure booster or installing a water pressure regulator.
4. Leaking Flapper Valve
If water flows normally into the toilet tank but won’t fill up, the flapper valve is likely the problem.
The flapper valve is located at the base of the tank and connects to the toilet handle via a chain. When the handle is pulled, the flapper opens to allow water to rush into the toilet bowl.
However, a leaking flapper valve will cause water to leak constantly into the toilet bowl. This is called a running toilet and can’t allow the toilet tank to be filled with water.
The rubber flapper valve may leak if it is warped, worn out, or hardened. A metal flapper can also rust over time and deform.
Sometimes, there may be a buildup of debris or minerals under or around the flapper. This will prevent the flapper from sitting properly and sealing the valve seat.
In some rare cases, the lift chain holding the flapper valve may get caught under the valve. All of these will render the flapper valve ineffective.
5. Incorrectly Set Tank Lever
The tank lever is responsible for flushing the toilet when pulled. It is also connected to the flapper valve via a chain.
If the tank lever is not correctly set, it can cause the flapper valve to open prematurely. This will result in water constantly flowing from the tank into the bowl. As a result, the tank would never fill up.
The correct setting for the tank lever is when the flapper valve is in line with the flush valve opening. If it’s not, then readjust it accordingly.
6. Damaged Tank
Apart from all these, the no-fill toilet tank may be caused by a leaking tank. A leaking tank will definitely not hold water.
If the tank is damaged or cracked, it will likely leak out water and not get filled up. An easy way to know this is when you always see water on the toilet floor.
Other than that, check the tank for any cracks or holes. If you can’t spot any, then place a few drops of food coloring in the tank.
After 10-15 minutes, check the toilet bowl and the bathroom floor. If it’s stained with color, then there’s a good chance that your tank is leaking.
7. Partially Closed Shut-Off Valve
Finally, a reason why your toilet tank may not fill after flushing is a partially closed shut-off valve.
The shut-off valve is located underneath the shower tank and regulates the flow of water. It must be opened completely for water to rush into the tank at the normal volume.
If the toilet shut-off valve is closed, the toilet tank will not fill at all. If the valve is partially opened, there would be low pressure in the tank and water will only drip into the tank.
To check if the shut-off valve is the problem, simply turn it on and off. If it’s hard to turn or get stuck, then it may be partially closed. In this case, you will need a professional plumber to fix it for you.
How to Fix a Toilet Tank that Won’t Fill with Water?
If your toilet tank has stopped refilling after flushing, here are some simple DIY solutions to fix this problem:
1. Fixing a Faulty Fill Valve
If the fill valve is faulty due to clogs, do the following:
- Close the main water supply to the toilet tank.
- Flush the toilet to empty the tank and open the tank lid.
- Here, you’ll be using both hands. With your right hand, lift up the float ball/cup and hold the shaft of the fill valve tightly. With your left hand, gently hold and turn the fill valve cap slightly counter-clockwise to remove the cap assembly.
- Now, inspect the cap assembly for clogs, dirt, and debris. Check the seal, the holes on the valve seat, as well as the valve portion.
- After cleaning, completely turn on the water supply into the toilet tank to force out any debris inside. Be careful to avoid splashing water on your body.
- Once you’re certain that the fill valve is unclogged, reassemble the cap assembly. If the toilet fill valve is misadjusted, adjust it properly before locking it. This time around, press and turn the fill valve cap slightly clockwise to lock it.
If the fill valve is faulty due to old age, simply replace it with a new and genuine one. This video will help you to remove and replace a faulty fill valve-
2. Fixing a Bad Float Ball or Cup
- Shut the main water supply to the toilet and flush the toilet to empty the tank.
- Open the tank lid and check if your model has a float ball or float cup/cylinder.
- Float balls have float arms that connect to the fill valve using a plastic screw. With a screwdriver, gently turn this plastic screw clockwise to raise the water level allowed in the tank. Sometimes, you may just need to bend the arm slightly upward.
- Float cups also have a long plastic screw that you can turn clockwise to raise the level of water allowed in the toilet tank.
- When making this adjustment, don’t turn the plastic screw too much. Instead, turn it until the water level is about a half-inch below the overflow tube.
- Once you’re done with the adjustment, close the tank lid.
If the float ball/cup and float arm are worn out, replace them with new ones.
3. Fixing Low Water Pressure
Fixing low water pressure can be a bit tricky. You need to find out if the low pressure is only affecting the toilet or other areas in your home. If it’s only the toilet, you can
- Check the water supply pipes whether they are blocked.
- Carefully check for cracks and leakages in the water supply pipes
- Check the shut-off valve whether it’s partially closed.
If it affects other areas in your home, check the main water supply. This may not be a DIY fix, it’s advisable to call on a professional plumber to fix this problem.
One thing you may try is installing a water pressure booster. This will help to increase the water pressure in your home.
4. Fixing a Leaking Flapper Valve
- Shut the main water supply to the toilet and flush the toilet to empty the tank.
- Open the tank lid and detach the lift chain from the toilet handle arm.
- Disconnect the flapper valve from the overflow tube and remove it.
- If you have a metal flapper, check for rusts. If you have a silicone flapper, check if it’s warped or worn out. In either case, replace it with a new flapper valve.
- Make sure that you thoroughly clean the seat to allow the new flapper valve to sit properly and fittingly.
- Reconnect the pegs to the overflow tube and the lift chain to the handle arm
- Turn on the water supply to allow water into the tank. Check if water still leaks through the flapper valve. If there are no leaks, close back the tank lid.
5. Fixing a Damaged or Cracked Tank
The only solution to a damaged tank is a replacement. You never can tell the extent of the damage or crack.
If you continue to manage it, it may collapse and either cause an injury or flood your toilet with water.
The right step is to call on a professional plumber to repair or replace it with a new toilet tank.
However, if you can see the crack and it’s minor, you may be able to seal it with waterproof grout.
Empty the tank and dry it out completely before you apply grout in the crack. Allow the grout to be cured for at least 24 hours before you use a toilet tank liner kit on top of that. This will give your tank some extra protection against leaks for a while.
If you are able to apply grout perfectly, you should be able to save yourself from buying a new toilet tank anytime soon.
6. Fixing Partially Closed Shut-Off Valve
This problem requires a very simple fix. The first thing you should do is to check if the shut-off valve is closed or open.
If partially closed, open it by turning it in a counterclockwise direction. If your toilet has a push/pull valve, open it by pushing the valve handle.
If the valve is already in the open position, turn it a little more until water flows freely.
Partially closed valves are one of the most common reasons for toilets not to fill up with water after flushing. So, if you find that your shut-off valve is partially closed, don’t hesitate to give it a turn.
How to Fill Water in Toilet Tank After Applying the Fix?
We have explained above the various reasons why your toilet tank may not refill after flushing along with how to fix a toilet tank that won’t fill. Now, let’s discuss how to fill the toilet tank with water once you’re finished with the troubleshooting task.
First, make sure that you have applied any of the applicable fixes above to your no-fill toilet tank.
Now, open the water supply to allow water to flow into the toilet tank.
If you still notice a no or low water pressure, then something is still wrong with the tank and may need professional attention.
Otherwise, water should flow at the normal pressure into the toilet tank. The floating ball/cup should also stop the flow of water at the normal water level.
Now, you have a toilet tank that will fill after flushing.
How to Fix a Toilet Tank that’s not Holding Water?
If water flows into your toilet tank at the normal speed and volume but doesn’t stay in the tank, then something is either wrong with the tank or with the flapper.
Carefully check the toilet tank for cracks. It’s possible that the crack is little and dripping water away slowly.
When you see water constantly on the toilet floor or on the body of the tank. It’s a sign that the tank is cracked and dripping water.
If you’ve been using the tank for a long time, you may consider replacing it with a new one. Otherwise, find out the crack and apply the grout as instructed above.
The problem can also be with the flapper. As discussed above, a rubber flapper valve can get warped, worn out, or hardened. A metal flapper can rust over time and deform. The flapper can also have a buildup of minerals, or debris. All of these will cause the flapper to sit loose and leak.
If the toilet tank is new, you may simply need to clean the clogs on the flapper. Otherwise, you need to replace the flapper with a new and suitable one. Follow the steps above to fix a leaking flapper.
If your toilet tank won’t fill or takes so long to fill after flushing, it indicates that something is wrong.
Since this won’t stop your toilet from functioning, it can be tempting to ignore the malfunctioning toilet parts.
If left ignored, these parts can fail completely, waste tape water, and raise your water bill significantly.
Luckily, this post has shown you how to fix your toilet tank that won’t fill with water after flushing.
If you follow these steps carefully, you should be able to fix your no-fill toilet tank. Watch this short YouTube video to guide your better-
Please note that this DIY guide is for instructional purposes. If DIY fails, don’t hesitate to call on an expert plumber to inspect your toilet.