SEAFLO 21 Series 12V Diaphragm Water Pump — 1.2 GPM, 35 PSI, Quiet Compact RV/Marine Model

The SEAFLO 21 Series is a compact 12V diaphragm water pump delivering 1.2 GPM and up to 35 PSI with self-priming, adjustable pressure, and extremely low amp draw for RV, marine, and off-grid freshwater systems.

Whether you’re converting a van, outfitting a small boat galley, or adding a simple sink to an RV, this pump is designed to supply a reliable single-fixture flow while conserving battery power and staying quiet. Built to potable-water and electrical safety standards, it balances compact size with serviceable features like an on-demand pressure switch, adjustable shut-off pressure, and self-priming capability.

How much flow and pressure can I expect from the SEAFLO 21 Series?

This model produces an open flow of approximately 1.2 gallons per minute (4.5 LPM) and has a factory shut-off pressure near 35 PSI (2.4 BAR). Expect steady delivery suitable for one sink or light-duty fixture without the bulk of larger pumps.

• Open flow: 1.2 GPM / 4.5 LPM
• Shut-off pressure: 35 PSI (adjustable)
• Designed for one fixture or light-duty water systems

Will this drain my battery or work with solar-powered setups?

The pump draws a nominal 4.0 amps at 12V, making it energy-efficient compared with larger models. Low amp draw and intermittent duty make it well suited to battery banks and small solar systems where conserving power matters.

• Voltage: 12V DC; draw: 4.0A
• Efficient for battery-powered vans, campers, and boats
• Intermittent duty cycle for short runs and on-demand use

Is the pump safe for drinking water and harsh environments?

Yes. Materials and certifications meet potable water and RV plumbing standards for North America, and the unit is ignition-protected for marine use. Corrosion-resistant components and a Santoprene diaphragm improve durability in wet and variable environments.

• NSF/ANSI/CAN 61 & 372, NSF 24, UL 778 compliant
• Ignition-protected build for marine installations
• Santoprene diaphragm and corrosion-resistant fittings

How easy is installation and what practical features help daily use?

The pump mounts using an industry-standard bolt pattern and uses 3/8" hose barb ports and 18 AWG leads for straightforward hookups. It includes an automatic pressure switch so the pump runs only when a tap opens, and the shut-off pressure can be adjusted to suit delicate fixtures or reduce cycling.

• Ports: 3/8" hose barb; leads: 18 AWG, 13" (33 cm)
• Self-priming up to 4 ft (1.2 m); dry-run and thermal protection
• Automatic on-demand pressure switch; adjustable pressure setting

Who is this pump for? If you need a quiet, compact freshwater pump for a single sink or light-duty system—such as van conversions, small RVs, boat galleys, kiosks, or auxiliary water circuits—the SEAFLO 21 Series is engineered for those exact scenarios. Its low amperage, potable-water compliance, simple installation, and 4-year limited warranty make it a practical choice for anyone wanting dependable pressure without a large footprint or heavy power consumption.