Rule bilge pumps may have similar cylindrical housings but use different pumping capacities and automatic-control arrangements. Standard DA models use external switching; 25SA checks for water on an electronic cycle; Rule-Mate pumps sense water internally. Identify the original MPN, hose outlet and electrical setup before replacing a pump.
Recognize the pump's control design
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.
Match GPH, hose barb and original MPN
The nominal flow figure is not a measurement at your boat's installed discharge height. Compare the old outlet size before changing hose.
| 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.
Identify a separate float switch
Rule 35A is an external float switch, not a bilge pump. The manufacturer's maximum switching current is 14 A at 12 V or 7 A at 24 V. The pump circuit needs its own correct fuse.
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.
Before changing the pump
Check the manufacturer's label, operating voltage, fuse, water-level control and physical strainer. Measure the discharge hose, examine the check valve arrangement and inspect wiring for corrosion or water entry.
Bilge pumps are not a substitute for finding and repairing leaks, and the boat's required safety or emergency pumping arrangements must be maintained.
Find the matching Rule pump or switch
Open the exact model to inspect its listing and current availability.
Rule 24DA
Non-automatic 360-GPH submersible pump. Requires suitable switching or external water-level control.
Check part details and availability
Rule 25DA
500-GPH standard pump with a 3/4-inch discharge, for manual or externally switched operation.
Check part details and availability
Rule 20DA
800-GPH standard pump; same nominal hose diameter as the 360 and 500 models but higher specified capacity.
Check part details and availability
Rule 27DA
1,100-GPH standard pump with a larger discharge fitting than the smaller DA models.
Check part details and availability
Rule 25SA
Automatic 500-GPH pump using periodic electronic sensing; not the same control design as a Rule-Mate.
Check part details and availability
Rule RM500B
Rule-Mate with built-in water-level sensing and included discharge check-valve arrangement.
Check part details and availability
Rule RM1100B
1,100-GPH Rule-Mate with internal automatic sensing and a larger hose outlet.
Check part details and availability
Rule 35A
Rule-A-Matic float switch for use with an appropriately rated separate pump; 14-A max at 12V, 7-A at 24V.
Check part details and availabilityRelated bilge pump identification
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