Fluidzon / Troubleshooting
Exposed Cistern Overflowing from Top
Water overflows from the top of the cistern, running down the outside of the cistern body
Identify the model first.
The same symptom can have different causes. Confirm the cistern label, installation generation and applicable manufacturer instructions. Use only safely accessible checks; ask technical support when unsure.
Help identify my cistern →Check 01
Identify the Overflow Source
On an AP Series exposed cistern, overflow from the top means the fill valve is continuing to supply water after the cistern has reached capacity. Remove the cistern lid and watch the fill cycle. The float should rise with the water level and shut the valve when water reaches 25 mm below the cistern rim.
Check 02
Check and Adjust the Float Arm
A float arm bent downward reaches shutoff too late. Gently bend the arm upward and observe whether the valve closes sooner. If the float ball is waterlogged (shake it to detect water inside), replace it. Also check that the float arm pivot is clean and moves freely — mineral scale can stiffen it.
Check 03
Test the Fill Valve
Manually push the float arm fully upward. If water continues to trickle past the valve, the diaphragm has failed. Replace the Fill Valve Assembly (Part AP100 FV01). Turn off supply, flush to empty, disconnect the supply pipe, unscrew the lock nut, swap the valve, set the float height, and test over two or three flush cycles.
These checks provide context for a support enquiry. Confirm any replacement article against the exact model drawing and manufacturer instructions.
Find the model parts catalogue →Technical support · UAE
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