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Seaflo 21-Series — Review & Specs | Pricepect | Pricepect

Home Water PumpsSeaflo 21-Series

Seaflo 21-Series — image 1

Seaflo

Seaflo 21-Series

Expert Review Analysis

The Seaflo SEAFLO 21 Series Water Pressure Diaphragm Pump is a compact 12V DC pump designed for on-demand water pressure in mobile applications like RVs and boats. It delivers 1.2 GPM at 35 PSI with self-priming capabilities up to 4 feet and features a built-in pressure switch for automatic start/stop operation.

✓ Best for: RV and caravan owners, boaters, and small-scale farmers needing portable on-demand water pressure for 1-2 fixtures, including boat sinks/showers, RV fresh water systems, caravan taps, and agriculture spraying where 12V battery power and intermittent duty apply.✗ Not ideal for: Applications requiring continuous water flow beyond the intermittent duty cycle, setups with more than two simultaneous outlets, or environments with dirty water sources that lack proper filtration to protect the pump internals.

Pros

✓Low power draw of 1.7-4.0 amps makes it efficient for battery-powered setups
✓Self-priming capability allows suction lift up to 4 feet for flexible installation
✓

Best Seller Rank History

Now#8Best#8Worst#12 +4

Lower = better sales rank

Rating Trend

Rating4.4/ 5Reviews1,841+410 reviews

Specifications

Design

Dimensions6.7" L x 3.9" W x 2.6" H (170 mm x 100 mm x 67 mm) mm

Weight1.25 lbs (0.57 kg) g

ColorBlack

MaterialSantoprene diaphragm, EPDM valves

Features

Self-PrimingUp to 4 feet (1.2 m) suction lift mm

Dry Run CapabilityYes

Built-in Check ValveYes

Pressure SwitchBuilt-in, adjustable, demand mode

Thermal ProtectionThermal overload/ignition protection

General

Max Temperature140°F (60°C) C

CertificationsCE/RoHS approved

ModelSFDP1-012-035-21

BrandSeaflo

Performance

Flow Rate1.2 GPM (4.4 LPM) LPH

Pressure35 PSI (2.4 bar) PSI

Duty CycleIntermittent

Motor TypePermanent magnet, sealed

Pump Type2-chamber positive displacement diaphragm

Ports

Port Size3/8" (10 mm) hose barb mm

Wire Length13.78" (35 cm) mm

Wire Gauge18 AWG AWG

Connector Type2-pin connector

Power

Voltage12V DC

Current Draw1.7-4.0 A mA

Materials

Diaphragm MaterialSantoprene

Valve MaterialEPDM

Protection

Thermal ProtectionThermal overload and ignition protection included

Certifications

Safety StandardsCE and RoHS approved

Operation

ModeDemand mode with built-in check valve and pressure switch

Dimensions & Weight

Height2.5 inches

Width3.8 inches

Depth6.5 inches

Weight0.000625 Pounds

Research Sources

seaflodirect.com

cnseaflo.en.made-in-china.com

hydrobuilder.com

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SEAFLO 12V DC 1.2 GPM 35 PSI 21-...

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User Reviews

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4.4

(1,797 reviews)

$32.99

SFDP1-012-035-21Black12

Dry-run capable design prevents damage when water supply is interrupted

✓Built-in pressure switch provides instant start and stop for on-demand flow

✓Soft mounts reduce vibration and noise for quieter operation during use

✓Hose barb connections simplify installation without requiring specialized tools

Cons

✗Intermittent duty cycle limits continuous operation to short durations
✗Flow rate drops significantly as system pressure increases toward shut-off
✗Performance may degrade if installed on uneven surfaces affecting priming
✗Lifespan can be shortened when pumping dirty or unfiltered water sources
✗Struggles to maintain adequate pressure for more than two simultaneous outlets

From Expert Reviews

Praised by Experts

✓Extremely efficient with very low current draw suitable for marine and RV use
✓High capacity output delivers reliable pressure for sinks and showers
✓Smooth and silent operation enhances comfort in enclosed mobile spaces
✓Compact design facilitates easy installation in tight spaces like boats

Criticized by Experts

✗Intermittent duty cycle restricts use for applications requiring continuous flow
✗Flow rate decreases under pressure reducing efficiency at higher PSI levels
✗Spec inconsistencies exist across documentation regarding exact flow rates

From User Reviews

Users Love

✓Strong initial flow rate effectively supports sinks and showers in RVs
✓Easy setup process with standard hose barb connections for quick installation
✓Durable construction withstands mobile use without frequent mechanical failures

Users Complain About

✗Occasional priming issues occur if the pump is not installed on a level surface
✗Noise levels increase noticeably under high demand or continuous operation
✗Shorter lifespan results when pumping dirty water without regular filtration
✗Inadequate performance when trying to supply more than two water outlets

Expert Opinion

Professional reviewers and editors highlight the Seaflo 21 Series as a professional-grade solution for marine and RV applications, praising its efficient low current draw and high capacity output. The compact design and silent operation are noted as ideal for boats, caravans, and agriculture, with built-in protections ensuring reliability for liquid transfer and spraying tasks.

What Users Say

Everyday users commonly praise the pump for its strong initial flow and ease of setup with hose barbs, noting its durability in mobile environments. However, recurring complaints include priming issues if not level, increased noise under high demand, and reduced lifespan when used with dirty water, with many noting it is best suited for one or two fixtures.

Common Complaints

Priming issues if not level, noise under high demand, shorter lifespan with dirty water, and struggle to supply more than two outlets.

How It Compares

vs. Shurflo 2088

Advantages

✓Lower weight at 1.25 lbs compared to 2.0 lbs
✓Lower maximum amp draw of 4.0A compared to 7.0A

Disadvantages

✗Lower shut-off pressure of 35 PSI compared to 45 PSI
✗Lower priming height of 4 feet compared to 6 feet

Choose Seaflo for battery efficiency and lighter weight, but choose Shurflo for higher pressure and better priming.

vs. Flojet Quad II

Advantages

✓Comparable flow rate of 1.2 GPM and pressure of 35 PSI
✓Similar self-priming capabilities for flexible installation

Disadvantages

✗Cheaper build quality compared to Flojet according to user feedback
✗Intermittent duty cycle similar to Flojet but with less robust construction

Choose Seaflo for a budget-friendly option with similar specs, but choose Flojet for potentially better build durability.

vs. Jabsco Par-Max

Advantages

✓Lower weight at 1.25 lbs compared to 2.5 lbs
✓Lower maximum amp draw of 4.0A compared to 3.5A (note: Jabsco is lower amp but heavier)

Disadvantages

✗Heavier and bulkier design compared to the compact Seaflo unit
✗Similar intermittent duty cycle but with significantly higher weight

Choose Seaflo for a lighter, more compact solution, but choose Jabsco if weight is less of a concern and similar quiet operation is needed.

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