Toilet tank diagram

Why is my Toilet Tank Not Filling Properly?

A common issue we come across with our local calls are people telling us that their toilet tank is not filling up properly and we would like to explain some reasons why and help all of you figure out possible solutions to fix this issue. Benjamin Franklin Plumbing of Cedar Rapids, Iowa is always here to help you with your plumbing issues, feel free to contact us for a routine inspection of your entire home’s plumbing and plumbing fixtures. 

This issue can be quite problematic for a residential home, people may start to notice that their tank is not filling up with water, and it may take more than one flush attempt just to clear the bowl. If you are a handy person, then this project might be up your alley and can be fixed by doing it yourself. But bear in mind, it is always advised to call a professional plumber to fix any plumbing issue. Here are some reasons why you may be faced with a troubling no-fill toilet tank. 

1. Float Ball Needs To Be Readjusted

From our experience, the float ball has been the most common culprit for this problem. If you refer to the diagram above, the float ball sits above the water in the tank. When the tank water reaches the optimal height, the float ball stops the inflow of water by moving the float arm to block the entry of water. The float ball being too low is usually the cause for not enough water entering your toilet tank. To fix this issue, you only need to give the float arm a slight bend upward, so that the ball goes higher and stops the entry of water much later. If this solution does not solve your toilet problem, and your float ball remains low, then you may need to replace the float ball completely. 

2. Adjusting the Fill Valve

If the toilet still proceeds to not fill properly from readjusting the float ball, then the problem may be resolved by adjusting the fill valves.

float valve

Toilet fill valves control the flow of water from the supply line to refill the tank between flushes. If your toilet’s fill valves use float arms, then the fix is to start by removing the toilet cap lid and locate the fill valve in the tank, it should be on the left side.

Place a flat-head screwdriver into the adjustment screw, and turn it clockwise to raise the fill valve which will allow more water to fill in, or lower the fill valve by turning the screw counter-clockwise if your tank needs less water. Flush the toilet after these adjustments and see if the water fills properly. 

float cylinder picture

If your tank is using adjusted cylinders, then again removed the toilet lid and find the fill valve that is located on the left side of the tank. Pinch the float clip on the side of the float valve and slide it up to let in more water, or slide it down to let in less water.

3. Toilet Not Filling Properly Could be Due to a Bad Trip Assembly

Your trip assembly is the part of the flush handle that is connected to the tank. This assembly could be positioned poorly, or it could block itself when the lid is on, this will result in the flush cycle not being completed correctly. Open the lid and inspect the trip assembly, if you notice that the trip assembly is bent, broken or worn out it is time to consider getting a replacement trip assembly to fix your filling problem.

4. Low Water Pressure

If this is the root of your issue with your toilet tank not filling properly then it may not be an issue with your toilet. This issue could be caused by old rusted pipes or even leaking pipes that prevent a strong enough flow of water to reach your home. If your home is an older property and you suspect you might have bad piping, it may be causing other irregularities in your other plumbing fixtures aside from just your toilet. Call a Benjamin Franklin Plumber to inspect your home’s plumbing, we will figure out the real issue to your problem and solve it promptly. 

We hope this post shed some light on the issue you are having with your toilet tank not filling properly. If you have any further questions, do not hesitate to call us at (319) 365-6792 and someone from our friendly staff will be there to assist you.