Rule 40-Rule-A-Matic-Plus Float Switch 20Amp Rule 40-Rule-A-Matic-Plus Float Switch 20Amp
Rule 40-Rule-A-Matic-Plus Float Switch 20Amp

Rule

Rule 40A Rule-A-Matic Plus Float Switch – 20 Amp Automatic Bilge Switch

$159.00 $99.00 Save 38%
Tax included.

Keep your bilge system running automatically and reliably with the Rule 40A Rule-A-Matic Plus Float Switch—a heavy-duty, industry-trusted solution for automatic bilge pump control.

Designed to activate your bilge pump when water reaches a set level, this float switch turns the pump on at approximately 51mm (2") and off at 19mm (3/4"), helping prevent flooding and maintain safe water levels onboard.

Built for harsh marine environments, the Rule-A-Matic Plus features a fully integrated, impact-resistant cover that protects the internal float mechanism from debris and jamming—one of the most common causes of switch failure.

With marine-grade 14-gauge “blocked wire” construction, the wiring is sealed to prevent water ingress, improving durability and reliability over time. A built-in test feature allows quick system checks, ensuring your bilge pump is always ready when needed.

Rated for pumps up to 20 amps, this float switch is ideal for a wide range of bilge pump systems on trailer boats, keelers, and larger vessels.

Key Features

  • Automatic bilge pump control – activates based on water level
  • 20 Amp capacity – suits most 12V bilge pump systems
  • Debris-resistant protective cover – reduces jamming risk
  • Built-in test switch – easy system checks
  • Marine-grade sealed wiring – prevents water intrusion
  • Mercury-free design – environmentally friendly
  • Durable construction – built for harsh marine conditions

Specifications

  • Brand: Rule (Xylem)
  • Model: 40A Rule-A-Matic Plus
  • Voltage: 12V / 24V / 32V DC
  • Max Pump Load:
    • 20A @ 12V
    • 10A @ 24V
    • 6.5A @ 32V
  • Activation Level: ~51mm (ON)
  • Deactivation Level: ~19mm (OFF)
  • Wiring: 14-gauge marine-grade blocked wire
  • Type: Mechanical float switch (non-mercury)

Ideal Applications

  • Automatic bilge pump systems
  • Trailer boats and small keelers
  • Coastal and offshore vessels
  • High-water alarm integration

Float switches like the Rule 40A are essential for automatic bilge management, helping protect your boat from water buildup and reducing the need for manual intervention.