Kohler’s Class Five toilets are known for their powerful flush performance and efficiency. But like any toilet, the fill valve inside the tank can wear out over time. If your Kohler toilet is running constantly, filling slowly, or making unusual noises, the Class Five Kohler fill valve may need adjustment or replacement. In this guide, we’ll explain how Class Five systems work, signs of a failing fill valve, and the best replacement options to keep your toilet working like new.
What Is a Kohler Class Five Fill Valve?
The Class Five system was introduced by Kohler to provide a strong flush with efficient water usage. The fill valve is the part of the toilet tank that refills water after every flush. In a Class Five toilet, the fill valve is designed to:
- Refill the tank quickly to prepare for the next flush
- Maintain the proper water level for optimal flushing
- Operate quietly with minimal splashing
- Provide long-term durability under frequent use
Signs Your Kohler Class Five Fill Valve Needs Replacement
Watch for these common symptoms of a bad fill valve:
- Constant running water – The valve isn’t shutting off properly
- Noisy refills – Hissing or gurgling sounds during refill
- Weak flush – Low tank water level prevents full flushing power
- Slow refill – Valve struggles to bring tank water up to level
- Water overflowing – Valve lets in too much water, spilling into the overflow tube
Best Replacement Fill Valves for Kohler Class Five Toilets
Here are the top replacement fill valves for Class Five toilets:
Kohler Genuine Part GP1083167 Silent Fill Valve Kit
Best Overall
- Designed for Kohler Class Five and other Kohler toilets
- Silent-fill technology for quiet operation
- Adjustable height: 7.75″–13.5″
Pros: OEM fit, whisper-quiet, long-lasting
Cons: Costs more than universal valves
Verdict: The most reliable choice for Class Five toilets. Check price here.
Kohler Genuine Part GP1138930 Universal Fill Valve
Best Premium
- Universal compatibility with most Kohler toilets, including Class Five
- High-quality OEM construction
- Quiet and efficient refill performance
Pros: OEM quality, versatile, durable
Cons: Higher price point
Verdict: Great premium option for long-term use. See it on Amazon.
Fluidmaster 400A Universal Toilet Fill Valve
Best Budget
- Adjustable height: 8″–14″
- Fits most Kohler Class Five toilets
- Widely available and easy to install
Pros: Affordable, dependable, DIY-friendly
Cons: Louder than OEM Kohler Silent Fill valves
Verdict: A budget-friendly universal replacement. View today’s price.
Comparison Table
| Product | Best For | Adjustable Height | Noise Level | Price Link |
|---|---|---|---|---|
| Kohler GP1083167 | Best Overall | 7.75″–13.5″ | Silent-fill, very quiet | View Price |
| Kohler GP1138930 | Best Premium | Adjustable universal | Quiet | View Price |
| Fluidmaster 400A | Best Budget | 8″–14″ | Moderate noise | View Price |
FAQ
Do I need a specific fill valve for Kohler Class Five toilets?
Yes. OEM Kohler fill valves like the GP1083167 are recommended for the best fit and performance. Universal options can work but may be noisier.
Can I adjust the water level in a Class Five fill valve?
Yes. Most Kohler fill valves include an adjustment screw or clip to raise or lower the water level in the tank.
How long does a Kohler Class Five fill valve last?
Typically 5–7 years depending on water quality and usage.
Can I replace the valve myself?
Yes. Replacement usually takes less than 30 minutes with a wrench and sponge to clear residual water.
What’s the quietest option?
The Kohler GP1083167 Silent Fill Valve is specifically designed for quiet refills, making it the quietest OEM choice.
Conclusion & Call-to-Action
A properly working Kohler Class Five fill valve ensures your toilet flushes powerfully and refills quietly. If you want the best OEM replacement, the Kohler GP1083167 Silent Fill Valve is the top choice. For a premium universal option, the Kohler GP1138930 delivers excellent performance. And if you want a reliable budget-friendly option, the Fluidmaster 400A is a proven universal valve that fits most Class Five models.
Order your replacement Kohler fill valve today and restore your Class Five toilet to peak performance.