Description The Rule-Mate RM500B is a 12V fully automated bilge pump rated at 500 GPH (1893 LPH), designed to provide reliable, sensor-controlled bilge water removal without the need for a separate float switch. Equipped with Auto Sense Intelligence, the internal water level sensor automatically activates the pump when water reaches approximately 2 inches (5 cm) and switches off when the level drops to approximately 3/8 inch (0.9 cm). This model incorporates an optimized impeller delivering up to 10% higher flow compared to previous generations at similar amperage draw. A built-in Thermal Cut-Off (TCO) provides additional protection for both pump and vessel. For 500–1100 GPH models, including the RM500B, features include backflow prevention to reduce residual water in the bilge, hidden air vents to minimise airlock in complex plumbing installations, and a threaded discharge outlet for easier installation and maintenance. If the internal sensor becomes fouled by debris or contaminated bilge water, the integrated back-up feature prevents continuous run conditions by reverting to a timed 2.5-minute cycle mode, protecting the vessel’s battery while maintaining automatic operation. The compact housing (approximately two-thirds the footprint of previous comparable models) allows installation in tighter bilge spaces. Technical Specifications Flow Rate: 500 GPH (1893 LPH) Voltage: 12V DC Operation: Fully automatic (integrated level sensor) Activation Level: approx. 2 in (5 cm) Shut-Off Level: approx. 3/8 in (0.9 cm) Threaded discharge outlet Built-in Thermal Cut-Off (TCO) Ignition protected Fully submersible Application Automatic bilge water removal Suitable for petrol and diesel engine compartments (ignition protected) Standalone automatic installation without external float switch
