DC 12V Liquid Level Sensor Relay Module – Auto Pump Controller
DC 12V Liquid Level Sensor Relay Module – Auto Pump Controller
DC 12V 2-in-1 Automatic Liquid Level Sensor Switch & Relay Module
Take full control of your water management with this compact yet powerful DC 12V Liquid Level Sensor Relay Module. Designed for both automatic water filling and automatic water pumping, this versatile 2-in-1 controller is the perfect solution for fish tanks, home water towers, irrigation systems, farm water supplies, poultry feeders, and more. Simply set your high and low probe positions — the relay does the rest, keeping your water levels perfectly maintained without any manual intervention.
Key Features
- 2-in-1 Dual Operation Modes: Connect your pump to the COM/NC port to automatically fill a water tank, or to the COM/NO port to automatically pump water out — two complete functions in one module.
- Wide Load Capacity: Supports up to 10A/250VAC, 10A/125VAC, 10A/30VDC — compatible with most standard water pumps, solenoid valves, and motors.
- Smart Level Detection: Three-probe system (HIGH, OUT, LOW) continuously monitors the liquid level and triggers the relay automatically when thresholds are crossed.
- Ultra-Low Standby Draw: Only 9mA standby current keeps energy use minimal even when running around the clock.
- No Dedicated Probe Required: Any standard household wire can be used as a probe — cost-effective and easy to set up.
- Compact & Robust: Measures just 44mm × 29mm × 19mm — small enough to mount almost anywhere.
- Isolated DC Power Design: Engineered for use with a well-isolated DC power supply for safe, reliable operation.
Technical Specifications
| Working Voltage | DC 12V (range: DC 10–15V) |
| Standby Current | 9mA |
| Working Current | 40mA |
| Dimensions | 44mm × 29mm × 19mm |
| Maximum Load | 10A/250VAC · 10A/125VAC · 10A/30VDC · 10A/28VDC · 10A/12VDC |
Interface Reference
- HIGH – Upper limit probe
- OUT – Output probe (reference)
- LOW – Lower limit probe
- DC+ – Positive power supply
- DC− – Negative power supply
- NC – Relay normally closed contact
- COM – Relay common contact
- NO – Relay normally open contact
How It Works
Auto-Fill Mode (COM → NC): When the water level drops below the LOW probe, the pump activates and fills the tank. Once the water rises above the HIGH probe, the pump stops — keeping your tank topped up automatically.
Auto-Drain Mode (COM → NO): Works in the opposite direction — the pump draws water out when the level exceeds the HIGH threshold and stops when it falls below the LOW threshold.
Applications
- Home water tower automatic supply systems
- Aquarium & fish tank water change systems
- Garden & farm irrigation controllers
- Poultry and livestock automatic watering feeders
- Solenoid valve and motor automation
- Conductive liquid level control in industrial settings
Important Notes
- Slight color variation may occur due to monitor settings and lighting conditions.
- Please allow ±1–3cm tolerance due to manual measurement.
- Probes (wires) are NOT included — any household wire works as a probe.
- Always use a well-isolated DC power supply for safe operation.
Made in Mainland China.
Package Includes
- 1× Liquid Level Sensor Switch Relay Module
For general electrical safety guidance when working with relay modules and automation components, refer to OSHA's Electrical Safety Resources.
Frequently Asked Questions
Q: Can this liquid level sensor relay module work with a 12V submersible water pump?
A: Yes! This module is designed to operate at DC 12V and can control pumps up to 10A/12VDC. Connect your 12V submersible pump to the COM and NO or NC terminals depending on whether you want auto-fill or auto-drain functionality.
Q: Do I need special probes for the liquid level sensor switch?
A: No special probes are required. Standard household wires can be cut and used as probes for HIGH, OUT, and LOW level detection. Simply position them at the desired water levels inside your tank or reservoir.
Q: Can I use this relay module for a fish tank water change system?
A: Absolutely. This module is well-suited for aquarium and fish tank automation. By connecting your pump to the appropriate relay terminals, you can set it to automatically pump water in or out based on the liquid level detected by the probes.
Q: Is this controller safe for continuous 24/7 operation?
A: Yes, with a standby current of only 9mA and a working current of 40mA, the module is energy-efficient and built for continuous use. Always ensure you're using a quality, well-isolated DC 12V power supply for safe long-term operation.