Tools and Materials
Product costs, availability and item numbers may vary online or by market.
Finding the Slow-Filling Toilet Problem
Step 1: Shut the Water Off
Depending on your water pressure, a tank usually refills in about three minutes. If it's slow to fill or it's not filling at all, try the shut-off first.
Make sure the water shut-off is completely open for maximum water flow. If it's not completely open, that may account for your slow-fill issues.
Step 2: Clean the Pump and Valve
If you've tried the water supply and that isn't the issue, try cleaning the pump and valve. Sediment can build up over time, and a good cleaning may fix the issue.
If the exterior of the fill valve has mineral buildup on it, use vinegar and a toothbrush to clean off the sediment. Once it breaks off, wash the valve with warm water and soap. Then rinse it off.
Next, disassemble and clean the fill valve and float cup. Turn the water off. Remove the valve top and cover the opening with an inverted cup. Hold the cup over the opening and turn the water supply back on to clear the debris.
Check the valve manufacturer's instructions or website for disassembly details.
Step 3: Install a Fill Valve
Check to see what type of assembly you have. If you have an older-style ball cock assembly (as shown in the image), try installing a new fill valve and float cup assembly.
Step 4: Conduct a Test
If you've checked the shut-off valve and cleaned the assembly and nothing seems to be working, then this may be a plumbing issue. Try this test.
If the supply line to your toilet is flexible, shut off the water and disconnect it at the toilet side. Run the line into a bucket. If the pressure coming from the shut-off valve is low, you may have a blockage in your water pipe. Unless you have experience working with pipes, it's best to call a plumber.
If you've cleaned everything and a plumber can't fix it, then it's probably time to purchase and install a new toilet.
Toilet Buying Guide
How to Install a Toilet
Watch our DIY Basics video: How Do I Unclog My Toilet?
Conclusion
Do you have a slow-filling toilet? Here are a few fixes you can try.
- Check the shut-off valve to ensure it's completely open.
- Sediment may have built up. Clean the pump and the valve.
- Try installing a new fill valve and float cup assembly.
- If the fixes don't work, you may have a blockage. Unless you have plumbing experience, it's time to call a professional.
If all else fails, it's probably time for a new toilet. Purchase a toilet from Lowe's and learn how to install it or we can do it for you.