Okay, Imagine you finally have your dream bathroom, complete with stunning indoor plants that don’t need a ton of sunlight and the world’s best affordable scented candle to boot… but there’s one major problem – your toilet won’t refill after a flush. The worst, right? Don’t fret, though. The solution to fix a toilet that wont fill might be easier than you think – plumber not required.
I have had this annoyance happen to me many times over the years, both in my home and others. The good news is that fixing this common problem isn’t very complicated. After all, the issue itself is pretty simple – your toilet isn’t getting enough water to refill. There are a few different things that could be going wrong, all of which I will go over today.
To be safe, I think it’s a good idea to know how a toilet works before attempting repairs, so we’ll start with that first. Once you know the basics, diagnosing the problem and fixing any issues is pretty easy. Ready to get to it? Let’s get to it.
How a Toilet Actually Works
The toilet is an essential part of any beautiful bathroom. Not only does it help you “do your business” with cleanliness, but it’s also responsible for managing many gallons of water throughout the year. Just like having perfect bathroom styling accents, eliminating any possible leaks, obstructions, or issues is necessary.
Nearly all toilets work the same way, meaning that learning how to fix a toilet that wont fill is generally a one-size-fits-all process. True, some individual parts may differ, but the overall design remains largely consistent.
Water runs in from the main water supply line to a branch line for your bathroom. From there, it goes through a supply line to your toilet’s fill valve. This valve normally stays shut thanks to the float ball attached to the float arm. This only opens the fill valve when the water level decreases, ensuring your toilet won’t keep running even when full.
Relatively simple, right? Well, there might not be too many parts, but failures in the toilet itself are actually the most common reasons people run into issues.
Before You Attempt Toiler Repairs: A Checklist
I generally work my way down a simple checklist, making sure I’ve “checked off all of the boxes” when diagnosing a toilet water issue. Consider this checklist when trying to learn how to fix a toilet that wont fill:
Is there any water on the floor? If so, then you may have an external leak. Try to find the source of the water if possible for a quick diagnosis.
Does the toilet keep running forever? In that case, your float ball & arm might need adjusting.
Is the toilet not filling up at all? There might be an issue with your water pressure.
Do you remember the last time you changed your flapper valve? If not, you might want to begin your diagnosis there.
Can you feel resistance when you go to flush? If not, it’s possible that the trip assembly has come undone or off-kilter somehow. Alternatively, it’s also possible that it’s obstructed in some way.
How to Fix a Toilet That Wont Fill: Checking the Bowl
Before you open up the back of the toilet, it’s a good idea to see if your toilet problem can be solved from the outside. Move any storage bags, racks, or other styles of bathroom storage items you might have away from the bowl, giving you complete visibility.
From here, you’ll want to start at the bottom of the tank. Does it look like there are any leaks? If so, then you might have a crack somewhere. Take a close look at the surface of the bowl to find any cracks.
Unfortunately, most cracks will be very thin, making the small leak very hard to detect. At least, that’s until there’s water all over your floor. If you do find one, stop using the toilet right away. Turn off the water supply to your toilet, and call a professional plumber to find out if you’ll need to replace your toilet.
With luck, repair will be an option, but it’s best to get a professional opinion on this one.
How to Fix a Toilet That Wont Fill: Checking the Water Pressure
Assuming everything looks alright from the outside, I’d probably continue your diagnosis by checking the water pressure, especially if you live in one of the many older homes with older plumbing. Any pressure issues should be fairly easy to find, as low water pressure can affect everything from your toilet to your shower system.
Of course, there isn’t a single solution when it comes to how to fix a toilet that wont fill. While it’s possible that the main water line pressure is low, there also could be a leak elsewhere. If the cold and hot water pressure from your other water sources appears normal, then the problem is most likely with your toilet setup itself.
To find out, I’d recommend starting by ensuring the main water line valve is completely open. From there, you can work your way back to the toilet, ensuring that everything is open and isolating the issue.
Adjusting the Float Ball A Common Fix
Another area where you might run into issues is with the float ball—or float cup—that’s attached to the float arm inside of your toilet’s tank. If you want to learn how to fix a toilet that wont fill then knowing about this common culprit will often help you quickly solve any issues at hand.
If the float ball isn’t set to the correct height then it can either prevent the toilet from filling up completely or fail to stop it from overfilling. Thankfully, adjusting or fixing this key point of failure is very easy.
First, make sure that the float ball is free of cracks, which can prevent it from floating. Assuming it’s fine, you’ll need to mess with the adjustment screw on the float arm. Generally, turning it right will allow more water in, while turning it to the left will allow less.
Once you’re done adjusting, flush your toilet. Make any additional adjustments as needed.
How to Fix a Toilet That Wont Fill: Checking the Overflow Tube
If the float arm wasn’t the problem then you might want to take a look at the overflow tube. Ideally, the water should come up to about half an inch below the top of the overflow tube. Since we already checked our float ball setup, we shouldn’t run into any issues with the water flow exceeding the length of the tube.
However, if the overflow tube has cracks or holes in it then it’s possible that the toilet won’t be able to fill up at all. You should check this as well to ensure it’s in working order. If it’s damaged, replacing it should be fairly easy and affordable. Just make sure to confirm the size of the old one before purchasing a new one.
How to Fix a Toilet That Wont Fill: Checking the Trip Lever Assembly
The trip lever in the trip assembly is another essential component of your toilet you’ll want to know about when learning how to fix a toilet that wont fill. Thankfully, it’s likely one of the toilet parts that you’re the most familiar with. The assembly starts with the handle on the outside the toilet, which connects to the trip lever on the inside of the toilet.
This lever is connected to the lift chain, which lifts the flapper valve up to allow the toilet to flush. It’s possible that your trip lever has become moved or damaged during routine use, giving you another potential issue to look into.
Just peering inside of the toilet should reveal whether the level is damaged or misaligned. Realign it if possible. If it needs to be replaced, check to see whether your particular toilet uses a universal trip lever, or if you’ll need to purchase one specific to that model to solve your toilet problem.
How to Fix a Toilet That Wont Fill: Checking the Toilet Flapper
Much like how an improperly sized door knob can prevent a door from closing correctly, an improperly installed or damaged toilet flapper can also cause issues. In this case, the main problem you’ll run into is poor flushing performance and water leaks.
The flapper is the valve located at the bottom of your toilet’s tank. It forms a seal across the flush valve, keeping water inside the tank until lifted by the flapper chain. Although a new flapper will generally form a perfect seal, you might run into issues if you’re using an old flapper.
Metal flappers—which have a tendency to degrade over time—are common in older toilets. Newer toilets generally use silicone flappers, but these can fail as well. Not to worry, though, as you can easily pick up a replacement flapper at your local hardware store.
How to Fix a Toilet That Wont Fill: Cleaning the Fill Valve
So far, we’ve checked the water pressure, the float ball, the float arm, the overflow tube, the flapper, and the toilet bowl itself. If you’ve made it this far and still haven’t found the issue then you might be dealing with a faulty fill valve.
On the other hand, the toilet fill valve might also just be dirty. You’ll have to tear it apart to see. To do so, first drain the toilet and turn off the water. Holding the shaft of the fill valve from the bottom, twist the valve cap counterclockwise until you can remove it.
From here, check for debris in the holes on the valve seat. Use water to spray any debris out of these holes. Newer toilets shouldn’t have debris issues, but valves from older toilets should be replaced every five years or so.
Removing debris is a great short-term solution. However, if the problem repeats itself then it may be worth looking into getting a water filtration system to help prevent buildup in the future.
Now You Know How to Fix a Toilet That Wont Fill
Having a clean home isn’t enough – you want functionality as well! Fortunately, fixing a toilet that won’t fill is usually an easy fix. After all, you don’t want to pay for an expensive plumbing repair when you could do it yourself.
I hope you’ve found this article on how to fix a toilet that wont fill helpful. If not for now, then for later. Consider checking out my other posts on the various bathroom projects I’ve done, and let me know all about your bathroom-based wins & woes in the comments below.
Have a great week!
Frequently Asked Questions Related to How to Fix a Toilet That Wont Fill
How do you unclog a toilet fill valve?
First, you’ll want to turn off the water supply. From here, grab the shaft of the fill valve, then remove the top cap. Clean out debris then reassemble before testing the toilet.
How do you tell if toilet fill valve is broken?
Aside from leaking, you might notice a never-ending flow of water, weird noises, intermittent running water, or a tank that refuses to refill.
How does a fill valve get clogged?
Ideally, your fill valve will never get clogged. If it does, it’s generally a combination of debris, mineral deposits, and sediment in your water supply. If you’re having issues with clogging then simply picking up & installing a water filtration system should solve this problem.
How long do toilet fill valves last?
It depends, but you can generally expect your toilet fill valve to last between five to seven years before needing routine toilet repair.
When I flush my toilet it fills up with water then slowly drains?
You might be experiencing a clog! Check your toilet and your drain line to isolate any potential problems.
How can I make my toilet fill up more?
If a simple push of the flush lever isn’t giving you enough water then you’ll need to adjust the float ball and/or arm. Some toilets will require a screwdriver to adjust, while others can be easily adjusted by hand.