Rule LoPro LP900S Low Profile Automatic Submersible Bilge Pump

The Rule LP900S LoPro is a low-profile 12V bilge pump rated at 900 GPH (3,407 LPH; approx. 57 litres/minute). It measures only 58.4 mm high and supports automatic level-sensing or 2.5-minute timed water-check operation.

The Rule LP900S is designed for shallow bilges and restricted spaces where a conventional upright pump cannot fit. Its rotating discharge body, horizontal or vertical mounting options and supplied port adapters allow the outlet to be aligned around structural members and other equipment.

Product Identification

• Brand: Rule
• Product name: Rule LoPro LP900S Automatic Submersible Bilge Pump
• Model / part number: LP900S
• Marine Scene SKU: CW-LP900S
• Product category: Low-profile automatic bilge pump
• Rated open flow: 900 GPH (3,407 LPH; approx. 57 litres/minute)
• Voltage: 12V DC
• Current draw: 4A
• Recommended fuse: 7.5A
• Quantity supplied: One pump

What Is the Rule LP900S Bilge Pump Used For?

This pump is used to remove nuisance bilge water from boats with limited vertical clearance, including shallow bilge compartments beneath floors, engines or machinery.

What Is Included?

• One Rule LoPro bilge pump
• 19 mm, 25 mm and 28 mm straight discharge ports
• 19 mm 90-degree discharge elbow
• Integral backflow-prevention valve system
• Factory-fitted marine wiring

What Is Not Included?

• Discharge hose, through-hull fitting and hose clips
• Cable extensions, waterproof connectors and 7.5A fuse
• Optional panel switch

Which Boats and Bilge Systems Is This Pump Suitable For?

• For 12V DC marine electrical systems.
• Compatible with 19 mm, 25 mm or 28 mm straight hose connections, plus a 19 mm 90-degree elbow supplied with the pump.
• Can be mounted horizontally or vertically.
• The discharge body rotates to simplify hose alignment.
• No separate float switch is required for automatic operation.

How Does the Automatic Operation Work?

Automatic level-sensing or 2.5-minute timed water-check operation

How Do I Select the Correct Pump?

Confirm the complete installation rather than selecting by nominal GPH rating alone:

• Supply voltage: 12V DC
• Rated open flow: 900 GPH (3,407 LPH; approx. 57 litres/minute)
• Installed space: 237.5 x 58.4 x 58.4 mm (L x W x H)
• Circuit protection: 7.5A

Does the Published Flow Equal the Installed Flow?

No. The nominal capacity is an open-flow rating. Actual output reduces as discharge head, hose length, bends, restrictions and electrical voltage drop increase. Use the published flow-at-head figures where available and keep the discharge route as short and unrestricted as practical.

Construction and Design

• Backflow prevention: Integral check-valve arrangement
• Thermal protection: Built-in thermal cut-off
• Ignition protection: Yes
• Standards: CE; ISO 8849; ISO 8846
• Mounting: Horizontal or vertical
• Discharge body: Rotating for hose alignment

Installation and Safety

Select the mounting orientation that keeps the inlet at the lowest practical bilge point while allowing access for cleaning. Use the largest practical discharge route with minimal bends, provide anti-siphon protection where required, keep electrical joints above the maximum bilge-water level and fit a 7.5A fuse close to the power source. Test the complete system after installation.

Maintenance

Inspect and test the complete bilge-pump system regularly and before extended passages. Reduced flow, repeated fuse failure, unusual noise or slow switching requires investigation before the vessel is used.

• Remove debris from the strainer and impeller area.
• Inspect the discharge hose, clips, through-hull and anti-siphon arrangement.
• Check the wiring, fuse, terminals and control switch for heat, corrosion or damage.
• Keep the automatic sensor or float-switch movement clear of oil, dirt and debris.
• Test manual and automatic operation after cleaning or service.
• Replace damaged components rather than operating an unreliable bilge system.

Key Features

• 900 GPH (3,407 LPH) nominal open-flow capacity
• Low-profile 58.4 mm-high body
• 12V DC, 4A current draw and 7.5A recommended fuse
• Horizontal or vertical installation
• Rotating discharge body and four supplied port options
• Built-in thermal cut-off and backflow prevention
• Ignition protected; CE, ISO 8849 and ISO 8846 compliant

Frequently Asked Questions

What is the difference between the LP900S and LP900D?
The LP900S has integral automatic sensing and timed-check modes. The LP900D is non-automatic and uses an external float switch and/or panel switch.

Which hose connection should I use?
Choose the port that matches the discharge hose and gives the least restricted route. Straight 19 mm, 25 mm and 28 mm ports and a 19 mm elbow are supplied.

Can the pump be mounted horizontally?
Yes. Both LoPro models support horizontal or vertical mounting.

Does the full 900 GPH reach the discharge outlet?
The 900 GPH figure is an open-flow rating. Installed flow reduces with head height, hose resistance, bends and voltage drop.

Specifications

Flow ratings are nominal open-flow figures. Installed output will reduce as discharge head, hose length, bends, restrictions and supply-voltage loss increase.

Flow ratings are nominal open-flow figures. Installed output will reduce as discharge head, hose length, bends, restrictions and supply-voltage loss increase.