Quick answer
A tank overflow that keeps running needs a plumbing investigation. A float-controlled inlet that does not stop filling is one possibility, but the technician should distinguish overflow from a leaking tank body or connection and identify any electronic level control. Do not block the overflow pipe or climb onto the tank to adjust it.
This guide concerns a domestic villa storage tank that is overfilling or appears to be discharging continuously. It is not a water-tank cleaning schedule, a pump-sizing guide or advice for fire-water systems. In an apartment building or any shared system, report it to facilities management rather than arranging unauthorised changes.
First response: limit risk without entering the tank area
Keep people away from slippery water, affected electrics and any visibly unstable ceiling or tank support. Contact building or community maintenance promptly. If you already know the dedicated isolation point and can reach it safely without tools, water or height exposure, follow the property's established shutdown procedure; otherwise wait for maintenance. Do not turn unfamiliar valves or disable a shared supply.
Never enter a water tank, lift a heavy lid by yourself, climb onto its shell or attempt work from an improvised ladder. Do not cap an overflow to stop the visible discharge. Ask the contractor to plan safe access, water isolation and any electrical isolation for pumps or controls. If the water appears contaminated, seek appropriate professional advice before using it for drinking or cooking.
Overflow, leaking connection or damaged tank?
| Visible clue from a safe location | What to have checked | Why the quotation changes |
|---|---|---|
| Water leaves the designated overflow outlet while the tank fills | Inlet shut-off, float movement/condition and the actual level-control arrangement. | A compatible mechanical valve is different from electronic control work. |
| Water appears around a fitting or joint | Connection, seal and tank-wall interface; establish whether the tank is overfilled. | Replacing a float alone may not address a leaking connection. |
| Wet tank wall, seam or base | Tank body, support and the source of water; stop assumptions based only on a puddle. | Tank repair or replacement needs a different assessment and access plan. |
| Filling or discharge comes and goes unexpectedly | Record timing and identify inlet/control operation, not just the pump sound. | An intermittent fault may require observation and control testing. |
DEWA identifies tank bodies, connections and positioning as possible sources of tank leakage. Its guidance supports professional maintenance rather than treating every wet tank area as the same valve fault. A provider should show where the water originates before recommending a part.
How a float valve fits into the system
A mechanical float valve responds to the water level to control the inlet. Some installations instead, or additionally, use level switches and powered controls. A tank can therefore require a valve, a control investigation or neither, depending on what has failed. Ask which device actually stops filling in your installation and which test demonstrates the defect.
Keraflo's KB float-valve description shows that even mechanical valves have model-specific opening and closing behaviour. The replacement must suit the installed inlet, pressure, tank arrangement and intended use; a similar-looking float is not enough. This is a specification question for the technician, not a reason to bend an arm or alter a level setting yourself.
Dubai price references: compare the same scope
Public offers checked on 17 September 2026 provide limited context, not a Bestimate market average. These are indicative planning references, not quotes; access, valve type, controls, materials, timing and provider assessment change the total.
| Public offer | What was advertised | Important exclusions or uncertainty |
|---|---|---|
| Plumber Dubai: standard float-valve replacement | AED 150–300, parts and labour in its price table. | Confirm valve specification, access, isolation, VAT and post-repair testing. The same page mentions a lower assembly figure separately; do not treat that as the complete installed job. |
| Chill & Flow: tank-service offer | Replacement labour for foot/float valve advertised as included when booking its water-tank service. | Conditional bundled labour, not free valve parts or a free standalone repair. Confirm the tank-service total and eligibility. |
| Electronic control, difficult access or tank-body repair | Inspection-based quotation. | No comparable fixed price established in this review; do not apply the standard mechanical-valve reference. |
A foot valve and a float valve have different functions. An offer mentioning both does not mean both need replacing. Ask providers to name the failed part and keep optional tank cleaning, pump work or structural repairs outside the base repair unless evidence justifies them.
The completion test matters as much as the new part
- Identify the inlet/control system and record the reason for the repair; specify the replacement part and whether any adjacent fittings are included.
- Agree water shutdown duration and who informs occupants. Ask how pumps or other equipment will be protected during the work.
- Include suitable safe access, containment and restoration of any cover or access arrangement that was disturbed.
- Ask the provider to demonstrate correct filling shut-off and inspect for leakage under the appropriate operating conditions, rather than leaving immediately after fitting a part.
- Record remaining defects, parts and workmanship support separately, any return-visit terms, VAT and making good. If the cause remains uncertain, require that uncertainty in writing.
What to send with the request
Describe where the water is visible, whether it is constant, when it began and whether recent tank cleaning or plumbing work preceded it. Share existing service records or model details privately if available. A safely taken wide photo can show access constraints; do not climb to provide one. Crop or blur addresses, unit numbers, names, account details and equipment serial labels from shared images.
If cleaning is also needed, compare it separately using the Dubai water-tank cleaning guide. For a pump that cycles or loses pressure, use the water-pump repair guide. The plumbing service selector helps keep supply, drainage and fixture work distinct.
Read the Plumbing Services in Dubai service overview before enquiring. Confirm that the provider accepts the precise repair or installation scope described here, then send the same brief when comparing quotes.
Request an overflow diagnosis and a defined repair
Compare plumbing quotes for free with the tank access, valve or control specification, isolation, testing and tax made clear. Do not approve unrelated replacements without an explanation.
Compare Quotes for FreeFrequently asked questions
Is a continuously overflowing tank always a float-valve fault?
No. A faulty inlet valve is one possibility, but the provider should identify the control arrangement and confirm that the water is actually from the overflow rather than a connection or tank-body leak.
How much is a float-valve replacement in Dubai?
One reviewed provider advertises AED 150–300 for standard parts and labour. That is a limited reference, not a universal quote. Access, valve specification, VAT, controls and testing need confirmation.
Can I block the overflow pipe until the plumber arrives?
No. Do not cap or obstruct the overflow. Keep clear of the affected area and obtain maintenance help to control the incoming supply safely.
Does tank cleaning include a new float valve?
Not automatically. One reviewed offer includes replacement labour only when its tank service is booked. Confirm parts and the complete package price; cleaning and repair are different scopes.
Will a new pump stop the tank overflowing?
Not necessarily. The filling control and source of discharge need to be established first. Do not accept pump replacement as a substitute for an inlet or level-control diagnosis.
What should be checked before the technician leaves?
Ask for the appropriate filling/shut-off test, leakage checks, restoration of access covers and a record of any unresolved defect. The exact procedure depends on the installed system.
Sources and review method
Reviewed 17 September 2026 by Bestimate Editorial Team. An official maintenance source, manufacturer operation guidance and two differently scoped Dubai offers were checked. Prices were not averaged; no tank-life, water-savings or guaranteed-response claim is adopted.
