How To Replace Your Toilet Fill Valve
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If your toilet isn’t working correctly, your drainage pipe might be clogged or your fill valve assembly might be malfunctioning. Either way, it’s important to act quickly because these problems can lead to water leaks, blockages, and constantly running water. Hire a professional for toilet repair or fix your toilet yourself as a do-it-yourself (DIY) project to minimize the risk of water or sewage damage. Read the step-by-step guide below to help determine whether your toilet fill valve has gone bad and how to replace the toilet fill valve if needed.
Why Replace a Toilet Fill Valve
Toilet fill valves are the mechanisms that control the flow of water in and out of toilet tanks. When you press the flush lever down, the gasket at the bottom of the tank lifts up and sends water to the bowl. When the water level in the tank gets low enough, the fill valve activates and allows water from the supply line into the tank.
The two most common types of toilet fill valves are ballcock and floatcup styles. Both have floating mechanisms that automatically open and shut the valve as water levels fall and rise. If that alignment is off, your toilet tank may not fill enough or will continuously overfill.
You can readjust a poorly set toilet fill valve, but the problems below require a completely new valve:
- Constantly running toilet: The three biggest culprits behind a constantly running toilet are a short chain that doesn’t allow the flapper to fully close, a broken flapper, or a float that’s not positioned correctly.
- Loud water fill: If your fill valve continuously drips, runs loudly, or produces a hiss or whistle, you probably need a new valve.
- Problems with the entire assembly: You can easily purchase an entire fill assembly in a big box store such as Home Depot. Replacing the entire assembly is sometimes more efficient than trying to troubleshoot individual problems.
- Constant fixing: Toilet fill valves can break down over time, lose their seals, and become dirty with hard water buildup. If you have to frequently fix the fill valve, you may simply need to buy a new one.
- Slowly filling toilet tank: Toilet fill valves will slow over time due to worn components or hard water sediment that obstructs part of the line.
Replacing the fill valve entirely requires just a few tools, a new fill valve, and less than an hour of your time. It’s much less expensive than buying a new toilet.
Tools Needed for Toilet Fill Valve Replacement
Gather the materials below before you replace your toilet fill valve:
Below are the common household tools you need for this project:
- Adjustable pliers or a wrench to remove the nut
- Small bucket or plastic container to collect water
- Sponge or microfiber cloth to wipe the inside of the tank clean
- Towel for drips or spills
You don’t need specialized tools for this project, but you do need specialized parts. Visit your local hardware store to purchase a new toilet fill valve, or order one online. We recommend purchasing the entire fill valve assembly. This includes the fill valve, a new fill valve base, a refill tube, and the lock nut and gasket.
Modern valve kits don’t require Teflon or plumbing tape, as they include self-sealing, watertight hardware.
Removing the Old Toilet Fill Valve
Replacing an old toilet fill valve is simple. Follow the steps below to complete the project while minimizing drips or spills:
1. Shut off the local water
Find the toilet supply shut-off valve behind the toilet, and turn it to stop water from entering the toilet. If you see buildup or cannot easily turn the valve by hand, cover it with a towel and use your adjustable pliers or wrench to turn it. Apply steady pressure without forcing it shut.
2. Release the fill valve
Open the tank and flush the toilet to remove as much water as possible. Grab the back of the toilet fill valve base and release the manual locking ring that holds the top part in place. If this part is causing issues but the base is in good condition, you can simply remove this part and stop.
3. Remove the base of the fill valve
Place the plastic container under the water supply hose. Reach underneath the tank, and unscrew the supply line hose. Let it empty into the container. Use your adjustable wrench or pliers to loosen the nut that secures the fill valve base to the bottom of the toilet tank. Once the lock nut is off, you can pull the entire assembly out.
4. Let the water drain
Let the water drain into the waiting plastic bucket, and set the assembly in the bucket, too.
Before you move on to the next phase, wipe the inside of the tank clean to remove any buildup or debris. Make any necessary tank repairs at this time.
Installing the New Toilet Fill Valve
Follow these steps to install your new toilet fill valve:
1. Adjust the height of the fill valve
The central shaft of the toilet fill valve will rotate or click up and down, so you can match it to the height of the tank. The top should be high enough to sit one inch lower than the tank edge, which lets the overflow tub sit naturally in place.
2. Install the assembly
Line up the bottom of the assembly with the open hole in the tank, and slide the shaft into position so it sits firmly on the floor of the tank. Thread the lock nut around the threaded shaft by hand until it’s firmly in place, and then use your wrench or pliers to turn it and create a watertight seal that doesn’t require any tape.
3. Reattach the water line
Line up the supply line with the visible shaft of the assembly under the tank and hand-tighten the connection.
4. Feed the fill refill hose into the overflow tube
If the tube has a clip, snip the new refill hose until it’s short enough to fit over the clip/angle adapter easily.
5. Monitor the tank as you turn the water supply back on
Start by turning the supply valve in the opposite direction to open the connection. Inspect the connection for leaky drips as the tank fills up with water. Look at the inside of the tank to make sure the water is filling to a normal level. You may need to adjust the float so the tank doesn’t over- or under-fill. Perform a couple of test flushes, and then put the lid back onto the tank.
The project is complete. All that’s left to do is clean up.
Troubleshooting Common Problems
When you’re replacing the fill valve, you may encounter a few unexpected challenges. Prepare for these three common problems below:
The Supply Line Won’t Shut Off
If you live in a region with hard water and it’s been a while since you shut off the water supply, the valve might stick. Gently apply pressure by hand, or cover the valve handle with a towel and turn it with a wrench. If it stays stuck, you may need to call in a plumber.
The Toilet Fills Slowly
If you replace your old fill valve and the toilet still fills very slowly, the float may be misaligned. Low floats create a weak flush, but too-high flats will send water continuously through the overflow tube. Move the clip of the float until the water sits one inch below the top of the overflow tube.
There Are Water Leaks
If you see a water leak out of the bottom of the tank, you probably didn’t install the assembly correctly. Try tightening the lock nut without cracking it. If the assembly can tilt, take off the lock nut entirely and realign it so it sits properly along the threads.
Our Conclusion
If your toilet has a weak flush or is continuously running, the fill valve likely needs replacing. Homeowners can easily complete this home improvement job with just a couple of tools. We recommend replacing the toilet fill valve every five years or more frequently if you notice whistling, hisses, or lots of wasted dripping water.
FAQ About Replacing a Toilet Fill Valve
What is a toilet fill valve?
A toilet fill valve is an assembly that refills the toilet tank after a flush. It manages the water level within the tank and replenishes it to the correct height quickly and efficiently.
How do I know if my toilet fill valve is bad?
You know if your toilet fill valve is bad if your toilet is filling slowly or continuously running. The toilet flapper can also break down over time.
How often should I replace my toilet fill valve?
You should replace your toilet fill valve at least once every five years. If you have hard water, you may need to replace the flush valve more frequently.
Can I replace a toilet fill valve myself?
You can replace a toilet fill valve yourself. The project takes about an hour, and you’ll need a replacement fill valve and base, an adjustable wrench, and a bucket for catching water.
What is the average cost of a toilet fill valve?
The average cost of a toilet fill valve is between $10 and $30. However, the cost of hiring a plumber to replace it can vary from $60 to $150.
Cost data sourced from Fixr
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