Buying guide
Automatic Water-Level Controller: How It Works and Which One to Buy
Quick answer
An automatic water-level controller watches the water in your overhead tank (and often the sump). It switches the motor on when the tank level drops and off when the tank is full, so the tank does not overflow and you do not have to remember the pump. Choose a model that suits your motor (single-phase or three-phase), your tank distance and whether you need sump dry-run protection.
How it works
- Sensors in the overhead tank report the water level to the controller.
- When the level falls below the set point, the controller switches the pump on through the starter or a contactor.
- When the tank is full, it switches the pump off.
- With a sump sensor, it stops the pump if the sump runs dry, which protects the motor.
Types of controllers
- Float switch: a mechanical float in the tank. Simple and low-cost, but moving parts can stick over time.
- Electrode / probe sensors: metal probes at set heights. Reliable and widely used; probes need occasional cleaning.
- Wireless controllers: the tank sensor talks to the controller by radio, which avoids running a long cable from the terrace.
- Ultrasonic or display models: show the exact level and sometimes send alerts to your phone.
Dry-run protection
Running a pump without water can damage it. Dry-run protection stops the motor when the sump is empty or the pump is not drawing water. Only some models include it, so we list it clearly in the quote.
Check before you buy
- Motor type and rating: single-phase or three-phase, and the existing starter
- Distance between the tank and the motor (wired or wireless)
- Whether you have a sump and need dry-run protection
- Apartment or multi-tank setup: one controller or several
- Condition of the existing wiring
Try our water-level controller page to see how the system behaves, then send us your details for a quote.
Common questions
Can an automatic water-level controller switch my pump on and off?
Yes, with a compatible controller. It switches the pump on when the tank level drops and off when it is full. We check your motor and starter first.
Will a water-level controller work with my existing motor?
Most standard tanks and motors can be matched. Very old wiring, unusual motors or long pipe runs may need changes.
What is dry-run protection in a water-level controller?
It stops the pump when the sump is empty or the pump is not drawing water, which protects the motor from damage. Only some models include it.