Oct 07, 2025
In daily life, if your toilet tank fills slowly or does not refill at all, it usually means the toilet fill valve has worn out or failed. Replacing it with a new one can restore normal flushing performance. Fortunately, toilet fill valve installation is quite simple—just follow the correct steps carefully.
Preparation Before Installation
Before installing the new toilet fill valve, make sure to:
1. Turn off the water supply – Rotate the shut-off valve clockwise to stop the water flow.
2. Empty the tank – Press the flush button to drain all the water from the toilet tank.
3. Remove the old fill valve – Use a wrench to loosen the locknut at the tank bottom and detach the old fill valve and supply hose.
4. Choose the right replacement fill valve – Ensure the thread type and size match your region’s water supply connector for a leak-free fit.
Europe and Africa: G3/8
Middle East: G3/8 and G1/2
Asia and South America: G1/2
Peru: G7/8 or 15/16-14NPSM
North America: 15/16-14NPSM
Once everything is ready, you can proceed to install the new fill valve.
Installing the New Fill Valve
1. Adjust the fill valve height
Most fill valves consist of two sections connected by a locking clip. Before installation, adjust the height according to your old valve or the tank size to ensure proper water level control.
2. Set the float height
The float can be adjusted by rotating the adjustment rod or sliding the clip. The highest water level (shut-off point) should be about 15 mm below the top of the overflow tube.
If it’s too high, water will flow into the overflow tube continuously; if too low, flushing performance will be weak.
3. Insert the new valve into the tank
Insert the valve through the bottom hole of the tank. Make sure the rubber seal sits tightly against the inner wall to prevent leaks.
4. Tighten the locknut
From the outside of the tank, tighten the plastic nut by hand or with a wrench—but do not overtighten, as it may damage the threads or crack the tank, making future replacement difficult.
5. Reconnect the water supply hose
Attach the hose to the valve’s threaded inlet and ensure the connection is firm.
6. Install the refill tube
Connect one end of the refill tube to the fill valve outlet and the other to the overflow pipe on the flush valve. Make sure both ends are securely fitted.
Test for Leaks and Function
1. Turn on the water supply to let water fill the tank.
2. Check for leaks – Pay special attention to the seal at the base of the fill valve.
3. Confirm proper water level – The water should stop filling just below the overflow tube’s top.
If any leakage occurs, slightly tighten the locknut or re-position the rubber seal.
Summary
Installing a toilet fill valve can be summarized in five simple steps:
> Remove → Insert → Adjust → Secure → Test
As long as the seal is tight, the float height is set correctly, and all joints are leak-free, the new fill valve will work reliably for years.
For better performance, consider choosing a quiet fill valve or one with an adjustable height design, which helps reduce noise and improve water efficiency.
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