How do I fix a toilet tank that doesn't fill up?

Danielle Segev
by Danielle Segev

Hi everyone, I have an issue with my one toilet, the tank doesn't fill up! I would love to try and repair the issue on my own. Please could all you clever DIYers let me know how I could do this? Here is a picture of my toilet. Thanks so much.

how do i fix a toilet tank that doesn t fill up
  13 answers
  • Redcatcec Redcatcec on Feb 09, 2023

    There are a couple of reasons why your tank is not filling...

    1. The float ball is too low, the float ball regulates how much water enters the tank. To fix this take the float arm off and bend it slightly upward, this will make the float ball be at a higher level and allow more water to enter the tank.

    Or, you can replace the float ball very easily & it is not a big expense.

    2. It could be in the fill valves located on the bottom left, take a flat head screwdriver and turn it clockwise, this raises the fill valve and will let more water into the toilet.

    Then flush it to see if it worked and fills the tank. For another type of toilet, not sure which type you have, look for the fill clips on the side of the float valve and slide it up for more water to enter, or downward if there is too much water coming in.

    3. Another reason is it could be a trip assembly problem, either not installed correctly, broken, or bent. This is attached to the flush handle. You may have to replace or realign it.

    How is your water pressure? Check out your plumbing for corrosion or rust. If you have that, it is an expensive repair, but necessary.

    Best to you. You can handle this.

    • Danielle Segev Danielle Segev on Feb 09, 2023

      Thanks for the great reply. My water pressure is good and I will most definitely check for corrosion in the plumbing. Otherwise, I will most certainly try out your suggestions. Thanks again

  • The likely culprit is the fill valve. It may not seal anymore due to age. You can try cleaning it to make it seal better, or replace it.

  • GrandmasHouseDIY GrandmasHouseDIY on Feb 09, 2023

    My first guess would be the float that tells the water when and when not to shut off. We had the same issue due to calcium build up in the back of our tank. We have very hard water. A good cleaning and the float had no trouble floating all the way up again so the tank would completely fill. Since then I've added clorox toilet bowl tabs to the back of all of our toilet tanks and its a helped A LOT.

  • William William on Feb 09, 2023

    Great tips here. Check the float on the fill valve. It may be sticking or need to be adjusted. If no water is getting in the tank check that the water valve on the side of the toilet is open. Also the water valve may be internally damaged in the close position. If so it would need to be replaced. A photo of the inside of the tank would help. They all work the same but internals may be different.

  • Cheryl A Cheryl A on Feb 09, 2023

    here is a how to video these are easy to fix

  • Kathy Gunter Law Kathy Gunter Law on Feb 09, 2023

    Two usual causes: 1- your float in the tank needs to be adjusted or 2-the seal has deteriorated. The easiest and most "sure fire" solution is to get a replacement kit. Easy to install. Follow directions and watch a few youtube videos.

    One thing to keep in mind is to verify that it isn't filling rather than leaking out of the bowl. I had one that had the tiniest of leaks where the wax ring is and it was virtually undetectable. We replaced it and it was fine after that. It's nice to have 2 people on that because the toilet is heavy.

  • Janice Janice on Feb 09, 2023

    Locate the brand of toilet you have, then do a search on the manufacturer's website with key words of tank not filling, or adjusting the float. They're sure to offer specific advice about your particular toilet and how to remedy your problem. Some of the toilets have a chain attached from the handle going from outside to inside that can be adjusted to raise or lower the float which involves the amount of water drawn into the tank.

  • Indeed, as many have pointed out, it could be a few different things. I'd check the float first which is very easy to adjust. Knowing me, I'd skip right ahead and replace that fill valve which is also super easy to do. I've got an overview of how easy here:

  • Betsy Betsy on Feb 09, 2023

    Hi Danielle: I'm thinking that the float may not be adjusted correctly. The water should go up to about 1/2 inch below the overflow tube. Knowing the make of your toilet or the type of innards you have would be helpful. But, I'd check that and that there is no blockage or, that the flapper isn't being held open by the chain or that it's not worn out. You would notice that the toilet is running, if that's the case. But, I'd check the float first.

  • Deb K Deb K on Feb 10, 2023

    Hi Danielle, this is an easy fix for you even if you have absolutely no plumbing experience. Hope this helps you out. Depending on the style of flush kit you have, I have attached two videos that should be able to guide you. Take off the lid to the toilet tank and set it in a safe place, then locate the screw that attaches the float to the fill valve (usually on top of the fill valve). Using a screwdriver, turn the screw in small increments to adjust the water level. Clockwise will raise it and counterclockwise will lower it.

    Newer style flush

    Old style flush

  • Dee Dee on Feb 15, 2023

    I actually just did this. Mine had a screw by the flow valve and I was able to adjust the screw to go to the proper water level If you are losing water replace the flapper.

  • Johnavallance82 Johnavallance82 on Feb 16, 2023


  • Mogie Mogie on Mar 02, 2023

    A toilet valve usually starts to wear out after about 10 years and the valve is usually the problem.