It’s frustrating — you just cleaned your toilet’s fill valve to fix a problem, only to find that now the Fluidmaster fill valve won’t shut off. Instead of stopping when the tank is full, water keeps running, sometimes into the overflow tube. This wastes water, raises utility bills, and can cause constant noise in your bathroom.
Fortunately, this is a common issue with an easy solution. In this guide, we’ll explain why a Fluidmaster valve won’t shut off after cleaning, what quick fixes you can try, and the best replacement fill valves and repair kits to solve the problem permanently.
Quick Picks: Best Fluidmaster Replacements
- Best Overall: Fluidmaster 400AH PerforMAX High-Performance Fill Valve – Quiet, adjustable, and reliable shut-off.
- Best Budget: Fluidmaster 400A Universal Fill Valve – Affordable, simple, and effective.
- Best Premium: Fluidmaster 400CRP14 Universal Fill Valve & Flapper Kit – Full repair kit for long-lasting results.
Why a Fluidmaster Fill Valve Won’t Shut Off After Cleaning
If cleaning didn’t fix the problem, one of these issues is likely the cause:
- Debris under the seal: Even after cleaning, small particles can prevent the seal from closing completely.
- Worn valve seal: Over time, the rubber seal hardens and no longer seals properly.
- Float set too high: If the float adjustment is incorrect, water will continuously flow into the overflow tube.
- Damaged valve body: Cracks or warping inside the valve can prevent proper shut-off.
- Worn flapper: Sometimes the real culprit is the flapper leaking water, causing the valve to keep running.
Quick Fixes to Try Before Replacing
- Turn off the water and remove the cap again to re-check for hidden debris.
- Inspect the seal — if it’s cracked or hardened, replace it with a Fluidmaster seal kit.
- Adjust the float to lower the water level slightly below the overflow tube.
- Check the flapper for leaks; replace it if water is escaping into the bowl.
- If none of these work, the valve is worn out and should be replaced.
Detailed Product Reviews: Best Fluidmaster Fill Valves & Kits
1. Fluidmaster 400AH PerforMAX High-Performance Fill Valve
Who it’s for: Homeowners who want a durable, quiet, and universally compatible solution.
- Key Benefits: Adjustable height, precise shut-off, water-saving features.
- Pros: Fits most toilets, quiet performance, dependable shut-off.
- Cons: Slightly more expensive than basic models.
Final Verdict: The best all-around replacement if your fill valve won’t shut off.
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2. Fluidmaster 400A Universal Fill Valve
Who it’s for: Anyone needing a simple, affordable replacement that just works.
- Key Benefits: Universal fit, time-tested design, easy to install.
- Pros: Budget-friendly, widely trusted, simple adjustments.
- Cons: Lacks water-saving features found in premium models.
Final Verdict: The go-to budget solution for a quick fix.
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3. Fluidmaster 400CRP14 Universal Fill Valve & Flapper Kit
Who it’s for: Those who want to replace both the fill valve and flapper to prevent future issues.
- Key Benefits: Complete repair kit, stops both overflow and flapper leaks.
- Pros: Great value, covers multiple problems, long-lasting solution.
- Cons: Slightly more installation time than replacing just the valve.
Final Verdict: Perfect for older toilets where more than one part is worn out.
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4. Fluidmaster PRO45 Quiet Fill Valve
Who it’s for: Households that value ultra-quiet operation and professional-grade quality.
- Key Benefits: Quieter refill, heavy-duty materials, strong shut-off seal.
- Pros: Premium build, less noise, longer lifespan.
- Cons: Higher cost than standard valves.
Final Verdict: Best choice if noise is a concern along with reliable shut-off.
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5. Fluidmaster 400H-002 Performax Universal Fill Valve
Who it’s for: Eco-conscious buyers who want to control water use.
- Key Benefits: Dual adjustments for water level and refill speed.
- Pros: Saves water, customizable, universal fit.
- Cons: Takes more time to set up correctly.
Final Verdict: A smart pick for fine-tuned water efficiency and control.
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6. Fluidmaster 402CARHRKP10 Complete Toilet Repair Kit
Who it’s for: Homeowners needing to replace all major toilet tank components at once.
- Key Benefits: Includes fill valve, flapper, and tank-to-bowl gasket.
- Pros: One purchase solves multiple issues, long-lasting repair, good value.
- Cons: More expensive and takes longer to install.
Final Verdict: The best choice for a full refresh if your toilet is older or has multiple issues.
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Comparison Table
| Name | Best For | Key Features | Price Link |
|---|---|---|---|
| Fluidmaster 400AH | Universal performance | Quiet, water-saving, reliable shut-off | View Price |
| Fluidmaster 400A | Budget replacement | Universal, simple, proven design | View Price |
| Fluidmaster 400CRP14 | Valve + flapper repair | Complete kit, prevents leaks | View Price |
| Fluidmaster PRO45 | Quiet upgrade | Professional-grade, noise reduction | View Price |
| Fluidmaster 400H-002 | Water efficiency | Dual adjustments, eco-friendly | View Price |
| Fluidmaster 402CARHRKP10 | Full rebuild | Complete repair kit | View Price |
FAQ Section
Why won’t my Fluidmaster fill valve shut off after cleaning?
Usually because debris is still trapped under the seal, the seal is worn, the float is set too high, or the flapper is leaking water into the bowl.
Can I fix the valve without replacing it?
Yes — try re-cleaning the valve, adjusting the float, or replacing the seal. But if the valve body is cracked or badly worn, replacement is necessary.
How long does a Fluidmaster valve last?
Typically 5–7 years depending on water quality and usage.
Is replacing a Fluidmaster valve difficult?
No. Most DIYers can replace it in 20–30 minutes with basic tools.
Should I replace just the valve or the entire kit?
If only the valve is failing, you can replace it alone. If your toilet is older, a full kit will save you from future problems.
Conclusion
If your Fluidmaster fill valve won’t shut off after cleaning, the issue is usually a worn seal, hidden debris, or an incorrect float setting. While quick fixes sometimes work, many valves simply wear out after years of use. Replacing your valve is an easy, affordable way to stop water waste and restore quiet operation.
For most homeowners, the Fluidmaster 400AH is the best overall solution. The 400A is a budget-friendly classic, while the 400CRP14 kit gives you a complete refresh. Whatever you choose, you’ll enjoy a toilet that shuts off properly and saves water.
Don’t let a constantly running toilet drain your wallet — get the right Fluidmaster replacement today and fix the problem for good.