Rule 14A / 16A 3700 Series Submersible Bilge Pump - 3700 GPH

The Rule 3700 Series combines the 12V Rule 14A and 24V Rule 16A in one high-capacity submersible bilge-pump listing. Both models provide a nominal open-flow capacity of 3,700 GPH (14,010 LPH; approximately 233 litres per minute), use a 38 mm (1-1/2 in) discharge connection and are supplied as non-automatic pumps for use with a separate, correctly rated control switch.

Designed for larger yachts, motor cruisers and workboats, the Rule 14A and 16A use a fully submersible centrifugal-pump design with a snap-lock strainer, stainless-steel shaft, blocked marine wiring, corrosion-resistant housing and built-in thermal cut-off. Select the model that matches the vessel's DC electrical system: Rule 14A for 12V installations or Rule 16A for 24V installations.

Product Identification

• Brand: Rule
• Product name: Rule 3700 Series Submersible Bilge Pump
• Models / part numbers: 14A and 16A
• Marine Scene SKUs: CW-14A and CW-16A
• Product category: Standard non-automatic submersible bilge pump
• Rated open flow: 3,700 GPH (14,010 LPH; approximately 233 litres per minute)
• Voltage options: 12V DC or 24V DC
• Discharge hose size: 38 mm (1-1/2 in)
• Quantity supplied: One pump in the selected voltage

What Is the Rule 3700 Series Bilge Pump Used For?

The Rule 3700 Series is used for high-capacity bilge drainage on larger yachts, motor cruisers and workboats. It removes nuisance water from the bilge through a fully submersible centrifugal pump and is intended for permanent marine installation.

Both models are non-automatic. For automatic operation, connect the pump to a suitably rated float switch, panel switch or other compatible control device.

What Is Included?

• One Rule 3700 Series submersible bilge pump in the selected voltage
• Integral or snap-lock strainer base
• Factory-fitted marine-grade electrical leads

What Is Not Included?

• Float switch or control panel
• Discharge hose, through-hull fitting and hose clips
• Cable extensions and waterproof electrical connectors
• Circuit-protection fuse
• Installation hardware not supplied with the packaged pump

Which Variant Should I Choose?

• Rule 14A: Select this model for a 12V DC vessel electrical system. It draws 10.1A at 12V and uses a recommended 25A fuse.
• Rule 16A: Select this model for a 24V DC vessel electrical system. It draws 6.9A at 24V and uses a recommended 15A fuse.

Do not connect a 12V pump to a 24V circuit or a 24V pump to a 12V circuit. Match the pump, switchgear, cable size and circuit protection to the vessel supply voltage and pump current.

Is a Separate Float Switch Required?

Yes, if automatic operation is required. The Rule 14A and 16A are standard non-automatic pumps and must be controlled by a separate, suitably rated float switch, compatible panel switch or another appropriate control device.

How Do I Select the Correct Pump?

Confirm the complete installation rather than selecting by nominal capacity alone:

• Supply voltage: Choose 14A for 12V DC or 16A for 24V DC.
• Rated open flow: Both models are rated at 3,700 GPH (14,010 LPH).
• Discharge hose: Both models use 38 mm (1-1/2 in) hose.
• Installed space: Allow approximately 184 x 124 mm (H x W).
• Circuit protection: Use the specified fuse for the selected model.
• Discharge head: Both models are recommended for a maximum discharge head of 4 m.

Does the Published Flow Equal the Installed Flow?

No. The 3,700 GPH figure is a nominal open-flow rating. Actual output reduces as vertical discharge head, hose length, bends, restrictions and supply-voltage loss increase.

Both models are rated at 2,900 GPH (10,977 LPH) at 1 m head and 2,450 GPH (9,274 LPH) at 2 m head. Keep the discharge route as short, direct and unrestricted as practical.

Construction and Design

• Pump type: Fully submersible centrifugal bilge pump
• Strainer: Snap-lock design for access to the impeller area
• Shaft: Stainless steel
• Wiring: Blocked marine wiring
• Housing: Corrosion-resistant construction
• Thermal protection: Built-in thermal cut-off
• Replacement strainer part number: 279
• Backflow prevention: No integral non-return valve stated
• Ignition protection: Yes
• Standards: CE and ISO 8849 marine bilge-pump standard

Installation and Safety

Mount the pump at the lowest practical point of the bilge while retaining access for strainer cleaning and servicing. Connect it to 38 mm (1-1/2 in) discharge hose and route the discharge to a correctly positioned outlet above the waterline.

• Use marine cable sized for the selected model's voltage, current and cable run.
• Fit the recommended fuse close to the power source.
• Keep all electrical joints above the maximum anticipated bilge-water level.
• Minimise hose length, bends and restrictions.
• Arrange the discharge system to reduce siphoning and backflow.
• Use switchgear rated for the pump load.
• Test manual and automatic control after installation.

Maintenance

Inspect and test the complete bilge-pump system regularly and before extended passages. Reduced flow, repeated fuse failure, unusual noise or unreliable 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.
• Test manual and automatic operation after cleaning or service.
• Replace damaged components rather than operating an unreliable bilge system.

Key Features

• Choice of Rule 14A 12V or Rule 16A 24V model
• Nominal open-flow capacity of 3,700 GPH (14,010 LPH)
• Approximately 233 litres per minute at nominal open flow
• High-capacity 38 mm (1-1/2 in) discharge connection
• Non-automatic design for use with a separate control switch
• Snap-lock strainer for routine cleaning access
• Stainless-steel shaft and blocked marine wiring
• Built-in thermal cut-off
• Ignition protected
• CE and ISO 8849 compliant

Frequently Asked Questions

What is the difference between the Rule 14A and Rule 16A?
The Rule 14A is the 12V model and the Rule 16A is the 24V model. Their nominal flow, dimensions, discharge size and flow-at-head ratings are the same, but their electrical current and recommended fuse ratings differ.

Is this pump automatic?
No. Both variants are non-automatic and require a separate float switch, panel switch or other suitable control device for automatic operation.

Which model should I use on a 12V boat?
Choose the Rule 14A. The Rule 16A is designed for 24V systems.

Will the pump deliver the full 3,700 GPH after installation?
Not necessarily. The published capacity is an open-flow rating. Installed flow reduces as discharge head, hose length, bends, restrictions and voltage drop increase.

Does the pump include a non-return valve?
No integral non-return valve is stated. Design the discharge system to control backflow and siphoning where required.

Can this pump replace routine bilge inspection?
No. A bilge pump is one part of the vessel's water-management system. Inspect the bilge, pump, hose, wiring, discharge outlet and control switch regularly.

Specifications

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