Automatic Float Switch for Bilge Pump – 113 x 54 mm (Float Switch)

This automatic bilge pump float switch is a reliable guard against flooding. Once wired to your pump, it continuously monitors the water level in the bilge. As soon as water rises to a preset point, the float tilts upward and closes the electrical circuit, activating your pump. After the pump expels the water and the level falls below the safe threshold, the float opens the circuit to shut the pump off, preventing it from running dry. With dimensions of 113 x 54 mm, this float switch is compact and can fit in almost any bilge compartment. Its housing is ultrasonically sealed (making it watertight) and made of durable plastic that won’t corrode in saltwater. The internal switching mechanism is designed to endure tens of thousands of on/off cycles, providing long-term protection for your vessel.

Installation is straightforward – the float switch has mounting holes and is secured to the bilge floor with screws. It is wired in series with your pump’s power lead: the positive lead of the pump is routed through the float switch. This way, when the float rises, the circuit closes and the pump receives power. The supported maximum current of around 15A means this switch can directly control most standard bilge pumps (typically up to 1100 GPH capacity). For very high-power pumps, using a relay is recommended, but for the vast majority of small to mid-sized boats, this float works perfectly on its own.

Usage & Benefits:

• Automate your pump: By adding this float switch, you turn a manual or non-automatic submersible pump into an automatic system. This is especially useful if your boat stays in the water unattended – during rain or boarding waves, the pump will activate on its own to protect the vessel from filling with water.
• Safety and peace of mind: Whether you step away from your boat briefly or you’re sleeping overnight onboard, you can trust that the system will react for you. The float switch also prevents pump damage by not allowing the pump to run “dry” once the bilge is emptied.
• Wide application: This model is a go-to choice for most small and medium boats – fishing skiffs, motorboats, sailing yachts up to ~30 ft. It’s compatible with both 12-volt electrical setups (common in trailerable boats) and 24-volt systems found in some larger yachts. Whatever the vessel, if the bilge pump doesn’t have a built-in float, this device completes the system.
• Low maintenance: The float switch itself requires minimal care – just periodically inspect the area around it and clear any debris (like leaves, sludge, or small trash) so it can move freely. Thanks to its sealed protective casing, the internal mechanism stays shielded from contamination, ensuring reliable operation.

In summary, the 113x54 mm automatic float switch is a small but extremely important device for any boat. It acts as the “brain” of your bilge pump, turning it on and off exactly when needed. With this switch, your boat is safer and you can relax knowing that even if you’re not on board, rising bilge water will not go unaddressed.