Choosing a Rule bilge pump involves more than selecting gallons per hour. The standard DA pumps require external control, the 25SA automatic model checks for water periodically, and Rule-Mate pumps have built-in water-level sensing. Compare the exact 12-volt models, discharge sizes and switching options below.
Standard, timed automatic and Rule-Mate systems
A pump intended to operate with an appropriate manual switch, external float switch or compatible control circuit.
Uses periodic electronic checks for water rather than an external float arm. Its control arrangement differs from Rule-Mate sensing.
An integral level sensor turns the pump on in response to water; a manual override can be provided when correctly wired.
Rule 12V bilge pump model comparison
The stated GPH is a nominal pump rating. Actual discharge flow decreases with hose length, elevation, fittings and restrictions. Choose the pump and plumbing using the vessel's requirements.
| MPN | Control | Nominal capacity | Discharge hose | Power | Fuse reference |
|---|---|---|---|---|---|
| 24DA | Standard | 360 GPH | 3/4 in | 12V DC | 4 A |
| 25DA | Standard | 500 GPH | 3/4 in | 12V DC | 4 A |
| 20DA | Standard | 800 GPH | 3/4 in | 12V DC | 7.5 A |
| 27DA | Standard | 1,100 GPH | 1 or 1-1/8 in | 12V DC | 7.5 A |
| 25SA | Timed automatic | 500 GPH | 3/4 in | 12V DC | 4 A |
| RM500B | Rule-Mate sensor | 500 GPH | 3/4 in | 12V DC | Check installation sheet |
| RM1100B | Rule-Mate sensor | 1,100 GPH | 1 or 1-1/8 in | 12V DC | Check installation sheet |
Fuse references for the standard and 25SA models are from Rule's model tables. Rule-Mate fuse selection must follow the exact model's installation instructions.
Using a Rule-A-Matic 35A control
Rule 35A provides separate water-level control for a suitable bilge pump. Rule lists a 14-amp maximum switching current at 12 V (7 amps at 24 V). Use a matching fuse, conductor and installation method for the actual pump.
Automatic Rule-Mate and timed 25SA models are not direct wiring equivalents to standard DA pumps with external 35A control. Confirm the original wiring, control method and switch ratings before changing any component.
Bilge drainage and electrical installation
Install the pump where it can remove water effectively and remain serviceable. Observe the pump's recommended fuse, wiring, hose routing and discharge location. Sealed marine wiring connections and the correct switch arrangement are essential.
Bilge pumps are not a substitute for finding and repairing leaks, and the boat's required safety or emergency pumping arrangements must be maintained.
Rule bilge pumps and the 35A float switch
Select the correct model below to review product details and availability.
Rule 24DA
Non-automatic 360-GPH submersible pump. Requires suitable switching or external water-level control.
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Rule 25DA
500-GPH standard pump with a 3/4-inch discharge, for manual or externally switched operation.
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Rule 20DA
800-GPH standard pump; same nominal hose diameter as the 360 and 500 models but higher specified capacity.
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Rule 27DA
1,100-GPH standard pump with a larger discharge fitting than the smaller DA models.
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Rule 25SA
Automatic 500-GPH pump using periodic electronic sensing; not the same control design as a Rule-Mate.
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Rule RM500B
Rule-Mate with built-in water-level sensing and included discharge check-valve arrangement.
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Rule RM1100B
1,100-GPH Rule-Mate with internal automatic sensing and a larger hose outlet.
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Rule 35A
Rule-A-Matic float switch for use with an appropriately rated separate pump; 14-A max at 12V, 7-A at 24V.
View product details and availabilityMore marine bilge equipment
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