SEAFLO 33 Series 12V Diaphragm Water Pump — 3.0 GPM, 45 PSI Self-Priming RV/Marine Pump with Auto Pressure Switch

The SEAFLO 33 Series 12V diaphragm water pump delivers up to 3.0 GPM at 45 PSI as a self-priming, on-demand fresh water solution for RVs, campers, boats and mobile water systems.

This compact, rugged pump is engineered to provide steady water pressure for sinks, showers and appliances in off-grid and onboard applications. Designed with a three-chamber diaphragm layout, the unit balances flow and pressure while protecting internal components with durable materials and thermal overload protection. The integrated pressure switch offers automatic on/off operation so water runs only when you open a faucet, and the rubber mounting base reduces vibration and noise for a more comfortable onboard experience.

How much flow and pressure will this pump deliver?

This model produces an open flow of approximately 3.0 GPM (11.3 LPM) and a shut-off pressure near 45 PSI (3.1 BAR), suitable for moderate-demand systems. Expect reliable performance for multiple fixtures when sized correctly for your plumbing.

• Open flow: 3.0 GPM (11.3 LPM)
• Shut-off pressure: ~45 PSI (3.1 BAR)
• Capable of supplying up to four fixtures simultaneously under typical conditions
• 1/2"-14 MNPT ports for standard RV/boat fittings

Can the pump handle installation challenges like suction lift and dry runs?

The SEAFLO 33 Series is self-priming and can draw water from up to about 6 feet (1.8 meters) of vertical suction lift, giving flexibility in tank placement. It is also designed to tolerate run-dry conditions without immediate damage, though continuous dry operation is not recommended.

• Self-priming suction lift: up to 6 ft (1.8 m)
• Run-dry tolerant for temporary dry conditions
• Thermal overload protection prevents motor damage from overheating
• Includes basic filter and barbed fittings for straightforward hookups

What materials and features support durability and quiet operation?

Critical wet-end components use EPDM valves and a Santoprene diaphragm to resist wear and chemical exposure in fresh water systems. A rubber mounting base and balanced three-chamber design minimize vibration and operational noise for marine and RV environments.

• EPDM valve material and Santoprene diaphragm for longevity
• Rubber-mounted base reduces vibration and noise
• Thermal overload protected motor for safety
• RoHS, SGS and ISO-compliant materials

What comes in the box and how long is the warranty?

The package includes the pump itself plus a 51S01 intake filter, two 51F001 1/2"-14 FNPT x 1/2" barb straight fittings, installation instructions and warranty documentation. SEAFLO backs this product with a four-year limited warranty that covers manufacturing defects under normal use.

• Included: pump, 51S01 filter, two 51F001 fittings, instructions
• Model: SFDP1-030-045-33, 12V operation
• Max recommended fluid temperature: 140°F (60°C)
• 4‑year limited warranty for added peace of mind

Who is this for: The SEAFLO 33 Series 12V 3.0 GPM pump is aimed at RV owners, boaters and mobile-home installers who need a dependable, compact fresh water pump with automatic pressure control. It fits applications that require moderate flow and pressure—such as small to mid-size RV water systems, marine galley and head setups, or off-grid cabins—where quiet operation, self-priming capability and durable materials are priorities. Choose this model when you want an easily installed, low-noise pump that balances performance and long-term reliability without complex controls.