Water Level Controller
Subtech digital water level controllers monitor overhead and underground tanks, automatically start the pump when the tank is empty, and stop it before overflow.
Two things happen when there is no water level controller: the tank overflows while the pump keeps running, or the pump runs dry and burns.
What Does a Water Level Controller Do?
A water level controller measures the water level in your overhead tank and sump, displays it on a panel-mounted indicator, and automatically starts and stops the pump based on the level readings.
The Subtech SL-100 is our digital water level indicator, a DIN-rail or wall-mount unit with a percentage-bar display that shows the tank level in real time.
Electrode-based controllers use conductive probes to detect water presence at specific levels.
For large tanks where electrode cables would be too long or impractical, float-switch-based controllers use a buoyant switch mechanism.
Why this matters for your facility
No More Tank Overflow.
The controller stops the pump the moment the tank reaches the upper level.
No More Dry-Run Motor Damage.
The controller monitors the sump level. When the sump is empty, the controller trips the motor before the winding temperature reaches the damage point.
Completely Automatic. No Operator Needed.
Once installed and calibrated, the system runs entirely on its own.
Visual Level Display at a Glance.
The SL-100 indicator shows the tank level as a percentage bar on a bright display.
Works with Any Pump Panel.
Our water level controllers are designed to interface directly with Subtech pump panels. They also connect to any third-party manual or automatic starter via a dry-contact relay output.
Low Maintenance. Stainless Steel Probes Last Decades.
Electrode probes are solid stainless steel rods with no moving parts.
Where Subtech panels are deployed
Apartment Complexes and Housing Societies
Overhead tanks in multi-storey apartments need continuous level monitoring and automatic pump control.
Hotels and Resorts
A 100-room hotel with continuous hot and cold water demand cannot rely on manual pump switching.
Hospitals and Medical Facilities
Hospital water supply is critical, for OT wash, sterilisation, dialysis, and general sanitation.
Municipal Reservoirs: UP Jal Nigam, Delhi Jal Board
Large municipal overhead service reservoirs and ground-level clear water reservoirs use Subtech level controllers.
Schools, Colleges, and Campus Institutions
Large campuses with multiple buildings and tanks benefit from centralised level monitoring.
RWA and Gated Community Installations
Resident Welfare Associations managing common water infrastructure use level controllers.
Water Level Controller Variants
All variants compatible with Subtech pump panels and most third-party starters via dry-contact relay output.
SL-100 Digital Water Level Indicator
Panel-mounted display unit showing tank level in percentage-bar format. Provides visual indication only. Does not control the pump directly.
Get quoteAuto Pump Controller with Electrode Probes
Full automatic pump start/stop based on overhead tank and sump levels.
Get quoteFloat-Switch-Based Controller
Uses mechanical float switches instead of electrode probes. Simple, robust, and inexpensive for tanks up to 5,000 litres.
Get quoteCombined Level and Flow Monitor
Adds a flow sensor on the pump discharge line to detect dry-run by zero-flow detection.
Get quoteTechnical Specifications: SL-100 and Electrode Controller
| Supply Voltage | 230V AC, 50 Hz |
| Probe Voltage | 12V DC (safe for potable water tanks) |
| Number of Levels | 4 (empty, 25%, 75%, full), expandable to 8 |
| Sensor Cable Length | Up to 50m standard; longer on request |
| Probe Material | Stainless steel 316 (potable water grade) |
| Output | Relay contact (dry contact, 5A at 230V AC) for pump panel |
| Operating Temperature | 0°C to 55°C |
Why Choose Subtech Water Level Controllers
Designed for Indian Grid and Water Conditions
Probe circuits are isolated from the mains supply. Surge protection prevents probe damage during monsoon lightning events.
Compatible with Any Pump Starter
The relay output interfaces with any manual or automatic pump starter. No proprietary connector, no lock-in.
Stainless Probes. No Maintenance.
SS-316 probes in potable water tanks last for decades.
25 Years of Water Management Products
Subtech has been manufacturing water level controllers since 1998.
Frequently asked questions
How does an electrode-based water level controller work?
Is the probe voltage safe for potable water tanks?
Can the controller work with both the overhead tank and the sump at the same time?
Ready to spec your water level controller?
Share your single-line diagram, load list or three months of electricity bills. Our engineers will respond with a custom BOM, quote and delivery schedule within 24 hours.