Jabsco 18590 Series Macerator Waste Pump, Self-Priming, Run-Dry Protection

Overview

The Jabsco 18590 Series is a range of DC marine macerator waste pumps for emptying holding tanks, fish boxes, and livewell receptacles where discharge is permitted. It uses a self-priming flexible impeller pump with a stainless steel wearplate and a stainless steel 4-blade cutter that grinds waste to a maximum particle size of 1/8 in (3 mm).

At open flow, the 18590 Series moves up to 12.5 GPM (47 LPM), and it can empty a typical 30 gallon (115 L) holding tank in less than 3 minutes. It self-primes to 5 ft when wet and 4 ft when dry, which helps in real installations where the pump is not mounted directly below the tank outlet.

The range includes 12V and 24V DC versions, so the selected model should match the vessel’s electrical system. The pump uses a 1-1/2 in hose barb and 1-1/2 in NPT male inlet with a 1 in hose barb outlet, making it practical for many sanitation and fish box discharge layouts.

Key features

• Available in 12 Volt and 24 Volt versions for matching the boat’s DC system without changing the pump layout.
• Self-primes to 5 ft when wet and 4 ft when dry, useful when the pump sits above or away from a holding tank, fish box, or livewell.
• Moves up to 12.5 GPM (47 LPM) at open flow and can empty a typical 30 gallon (115 L) holding tank in less than 3 minutes.
• Stainless steel 4-blade cutter reduces waste to a maximum particle size of 1/8 in (3 mm).
• 1-1/2 in (38 mm) hose barb and 1-1/2 in NPT male inlet with a 1 in (25 mm) hose barb outlet for common sanitation and discharge plumbing.
• Motor is a permanent magnet type with a stainless steel shaft, sealed end-bells, sealed bearings, a powder coated housing, and run-dry protection.
• Complies with USCG Regulation 183.410 and ISO 8846 MARINE for ignition protection.

Variants

The Jabsco 18590 Series is offered in two voltage configurations for different onboard DC electrical systems.

Across these 18590 Series variants, the verified pump configuration remains the same: the port sizes, stainless steel 4-blade cutter, priming ratings, run-dry protection, and sanitation or fish box evacuation use are shared; the DC voltage and electrical sizing change.

• 18590-2092: 12 Volt. This version fits 12V DC sanitation or fish box evacuation circuits and uses the fuse and wire sizing required for 12V installation.
• 18590-2094: 24 Volt. This version fits 24V DC electrical systems while keeping the same 18590 Series plumbing layout and pump configuration.

Installation and plumbing

The pump can be mounted in any orientation, although vertical installations should place the pump head below the motor. For waste systems, mounting close to the holding tank helps priming and flow. Suction connections need to stay airtight and free of sharp bends, since air leaks can make the pump run dry while it tries to prime.

The inlet can connect to 1-1/2 in hose or a 1-1/2 in female pipe fitting. Use a minimum 1 in ID discharge hose and route the discharge through a proper thru-hull arrangement. When the discharge is below the waterline, a vented loop at least 8 in above the waterline at all angles of heel or trim is required for safe plumbing practice.

Electrical and system integration

Wire the pump on an independent DC circuit with the fuse sized to the selected voltage: 25 Amp for the 12V version and 15 Amp for the 24V version. Wire gauge depends on the total circuit length from the power source to the pump and back to ground; keeping the run short helps reduce voltage drop, especially on 12V systems.

The operator should be able to hear the pump while it runs, since the sound changes when the tank or box is empty. Run-dry protection helps protect the impeller, but the pump should still be switched off once evacuation is complete.

Use cases on board

This pump suits boats that need controlled overboard discharge where it is legal, as well as sportfishing layouts that need to clear fish boxes or livewells with bait residue, scales, and ice particles. It is not intended to pass rags, kitchen towels, tampons, wet wipes, sanitary napkins, or similar items, so sanitation system use still depends on proper tank habits.

Maintenance and care

After a pump-out, flushing holding tanks with several gallons of clean water helps reduce sediment buildup in the tank and plumbing. The nitrile impeller and cutter are serviceable parts; avoid extended dry running and shut the pump off once the tank has been evacuated.