42 Series 12V Fresh Water Pump | 11.3LPM 55PSI

💧 SEAFLO 42 SERIES 12V FRESH WATER PUMP – 11.3LPM HIGH-PRESSURE ON-DEMAND PUMP

Compact Continuous-Duty Fresh Water Pump with Self-Priming, Dry-Run Protection & Internal Bypass Technology

💦 The SEAFLO 42 Series 12V Fresh Water Pump is designed for caravans, camper trailers, boats, 4WDs and other applications that need strong water pressure without installing an unnecessarily large pump.

Compact enough for tight installation spaces but capable of operating at pressures up to 55 PSI / 3.8 Bar, the 42 Series combines on-demand operation, continuous-duty capability, self-priming performance and dry-run protection in one versatile 12V pump.

Its internal bypass technology helps reduce excessive pump cycling when smaller amounts of water are being used, providing smoother operation across varying flow demands.

Whether you're supplying a caravan sink, shower or a more complete touring water system, the SEAFLO 42 Series offers substantially more flow and pressure capability than a small single-outlet pump while retaining a compact footprint.

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⚡ KEY FEATURES

💦 High-Flow Fresh Water Performance
Designed for applications requiring substantially more water delivery than a compact low-flow pressure pump.

🚿 Up to 55 PSI
Provides strong pressure capability for suitable caravan, camper, marine and touring water systems.

⚙️ On-Demand Operation
Designed for fresh water systems where the pump operates as water is required rather than needing to run continuously whenever the system is switched on.

⏱️ Continuous-Duty Rated
Suitable for applications requiring longer operating periods compared with intermittent-duty pump designs.

💧 Self-Priming
Designed to draw water through the inlet line when correctly installed, allowing greater flexibility when positioning the pump relative to the water tank.

🛡️ Run-Dry Safe
Provides additional protection if the water supply is temporarily interrupted or the tank runs empty.

🔄 Internal Bypass Technology
Helps reduce rapid cycling when smaller water flows are required, providing smoother operation across varying demand.

📐 Compact Design
Combines useful flow and pressure performance with a design intended for installations where available space is limited.

🔌 16AWG Electrical Leads
Supplied with approximately 9.4-inch electrical leads for connection into a suitable 12V circuit.

📜 2 Year Warranty
Backed by a two-year warranty for added peace of mind.

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🚿 BUILT FOR MORE DEMANDING FRESH WATER SYSTEMS

The SEAFLO 42 Series is a step up from compact low-flow pumps where more usable water pressure and greater flow are required.

It is well suited to applications such as:

• 🚐 Caravan fresh water systems
• 🏕️ Camper trailer plumbing
• 🚿 Shower systems
• 🚰 Kitchen and bathroom taps
• 🚤 Marine fresh water systems
• 🚙 4WD touring water systems
• 💧 Water transfer and dispensing

The combination of higher pressure capability and internal bypass technology makes the 42 Series particularly useful where water demand changes regularly between smaller and larger outlets.

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🔄 INTERNAL BYPASS TECHNOLOGY

One of the key features of the 42 Series is its internal bypass system.

In a conventional pressure-pump installation, very small water demands can sometimes cause the pump to repeatedly start and stop as system pressure rapidly rises and falls.

The internal bypass is designed to help the pump handle lower flow demands more smoothly, reducing unnecessary cycling and making operation more refined.

This can be particularly useful when a tap is only partially opened or a low-flow outlet is being used.

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💧 SELF-PRIMING DESIGN

The SEAFLO 42 Series is self-priming, giving installers greater flexibility in where the pump can be positioned relative to the water tank.

Unlike a centrifugal transfer pump that must remain submerged or gravity fed, the 42 Series is designed to draw water through its inlet line when installed correctly.

This makes it much better suited to permanent caravan, camper and boat fresh water systems.

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🛡️ SAFE TO RUN DRY

The pump is designed to tolerate dry running without immediate damage.

This provides useful protection if:

• 💧 The fresh water tank temporarily runs empty
• 🔧 The pump loses its water supply during servicing
• 🚐 The vehicle is operated before the tank has been refilled

⚠️ Dry-run capability is a protection feature rather than a reason to intentionally operate the pump without water for unnecessary periods.

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⏱️ CONTINUOUS-DUTY CAPABILITY

The 42 Series is rated for continuous duty, making it better suited to applications involving extended water use than pumps designed solely for short intermittent operation.

This can be particularly beneficial when running a shower, transferring a larger amount of water or operating a system where demand lasts for several minutes at a time.

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📊 FLOW, PRESSURE & CURRENT PERFORMANCE

As pressure increases, available flow decreases and current draw rises. This is normal behaviour for a pressure pump.

Open Flow / 0 PSI:
Flow: 2.85 GPM / 10.80 LPM
Current Draw: 3.9A

10 PSI / 0.69 Bar:
Flow: 2.27 GPM / 8.60 LPM
Current Draw: 4.5A

20 PSI / 1.38 Bar:
Flow: 1.96 GPM / 7.40 LPM
Current Draw: 5.1A

30 PSI / 2.07 Bar:
Flow: 1.59 GPM / 6.00 LPM
Current Draw: 5.8A

40 PSI / 2.72 Bar:
Flow: 1.32 GPM / 5.00 LPM
Current Draw: 6.3A

50 PSI / 3.45 Bar:
Flow: 1.11 GPM / 4.20 LPM
Current Draw: 6.7A

55 PSI / 3.80 Bar:
Flow: 0 LPM
Current Draw: 7A

The performance data shows why simply quoting a maximum litres-per-minute figure doesn't tell the complete story. Real-world flow depends on the pressure the pump is operating against.

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🚿 STRONGER PERFORMANCE UNDER PRESSURE

At approximately 30 PSI, the pump is still listed as delivering around 6.0LPM.

At approximately 40 PSI, it delivers around 5.0LPM.

This makes the 42 Series more suitable for applications requiring usable water pressure than a small transfer or low-pressure sink pump.

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⚡ CURRENT DRAW

The supplied performance data lists current consumption ranging from approximately 3.9A to 7A depending on pressure.

• 0 PSI – 3.9A
• 10 PSI – 4.5A
• 20 PSI – 5.1A
• 30 PSI – 5.8A
• 40 PSI – 6.3A
• 50 PSI – 6.7A
• 55 PSI – 7A

This remains a relatively manageable electrical load for many correctly designed caravan and auxiliary-battery systems.

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🔌 12V ELECTRICAL CONNECTION

The pump operates from a 12V DC electrical supply and includes approximately 9.4-inch long 16AWG leads.

These can be connected into a suitable switched and fused electrical circuit.

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🔋 SUITABLE FOR AGM & LITHIUM AUXILIARY SYSTEMS

The pump can operate from a suitable 12V auxiliary electrical system, including compatible AGM or lithium battery installations.

With a maximum listed current of approximately 7A in the supplied performance data, the pump represents a relatively modest load for most properly designed touring battery systems.

Always consider the total electrical load if the pump is operating at the same time as fridges, lighting, inverters or other accessories.

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📜 STANDARDS & WARRANTY

The SEAFLO 42 Series is listed as meeting or exceeding:

• ✅ RoHS standards
• ✅ SGS standards
• ✅ ISO standards

Warranty: 2 Years

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📋 TECHNICAL SPECIFICATIONS

Brand: SEAFLO

Series: 42 Series

Product Type: 12V Fresh Water Pressure Pump

Power Supply: 12V DC

Advertised Flow Rating: 11.3LPM

Maximum Flow Listed in Supplied Performance Chart: 10.80LPM / 2.85GPM

Maximum Listed Pressure: 55 PSI / 3.80 Bar

Duty Rating: Continuous Duty

Operation: On-Demand

Self-Priming: Yes

Dry-Run Safe: Yes

Internal Bypass: Yes

Maximum Listed Current Draw: 7A

Electrical Leads: 16AWG

Lead Length: Approximately 9.4"

Warranty: 2 Years

Standards Listed: RoHS / SGS / ISO

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🔧 INSTALLATION CONSIDERATIONS

• Use a suitable 12V DC electrical supply
• Mount the pump securely
• Use suitable fresh-water-rated hose and fittings
• Keep the suction line as unrestricted as practical
• Use correctly sized wiring if extending the supplied leads
• Install suitable fuse protection
• Confirm all hose connections are leak-free
• Protect wiring from moisture, abrasion and sharp edges
• Ensure the plumbing system is suitable for the pump's pressure capability
• Check the pressure rating of filters, fittings, taps and hoses before installation

⚠️ IMPORTANT: The pump can develop pressure up to the listed 55 PSI shut-off point. Make sure the complete plumbing system is appropriately rated.

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❓ FREQUENTLY ASKED QUESTIONS

Is this a good pump for a caravan with a sink and shower?

Yes. Compared with a small 3–4LPM pump, the 42 Series offers substantially more flow and pressure capability, making it much better suited to a caravan water system incorporating both a sink and shower.

Will it give me decent shower pressure?

It provides considerably stronger performance than a compact sink pump. The supplied chart shows approximately 6LPM at 30 PSI and 5LPM at 40 PSI, which gives a useful indication of real-world pressurised performance. Actual shower flow will depend on the shower head, hose, filters and plumbing restrictions.

Can I run a shower and tap at the same time?

Potentially, but the total available flow will be shared between both outlets. Whether performance is satisfactory will depend on the individual fixture flow rates and the pressure required. If strong simultaneous flow from several fixtures is essential, compare the total demand with the pump's performance curve.

Would this be better than the SEAFLO 21 Series 3.8LPM pump?

Yes if you need higher flow, stronger pressure or shower capability. The 21 Series is better suited to one or two small outlets and compact water systems. The 42 Series is the stronger option for a more complete caravan or camper plumbing system.

What does the internal bypass actually do?

It helps the pump accommodate smaller water demands without repeatedly cycling on and off as aggressively. This can make operation smoother when a tap is only partially opened or when a low-flow outlet is being used.

Do I still need an accumulator tank?

An accumulator tank is not listed as a requirement, and the internal bypass is specifically designed to help reduce cycling. An accumulator may still be useful in certain plumbing layouts, but it should not automatically be considered necessary for every installation.

Will the pump automatically operate when I use water?

The pump is specified for on-demand use. Once the water system and electrical supply are configured correctly, it is designed to provide automatic pressure-pump operation rather than requiring manual switching for each individual use.

Is it self-priming?

Yes. Unlike a basic centrifugal transfer pump, the SEAFLO 42 Series is self-priming and is therefore much better suited to permanent caravan and marine pressure-water systems.

Can I mount the pump above the water tank?

The self-priming design provides more flexibility in pump placement than a non-self-priming transfer pump. Exact mounting limits and maximum suction lift are not specified here, so confirm SEAFLO's installation requirements if the pump will be positioned significantly above the tank.

What happens if my water tank runs empty?

The pump is listed as dry-run safe, providing protection if water supply is temporarily lost. Once the tank is refilled, the self-priming design helps restore normal operation.

Can I leave it running dry permanently?

No. Dry-run protection is intended as a safeguard rather than a normal operating mode. Unnecessary prolonged dry operation should still be avoided.

Is it suitable for continuous operation?

Yes. The pump is specifically listed as continuous duty, making it more suitable for extended operation than an intermittent-duty model.

Will it run from a 100Ah lithium battery?

Yes. With a maximum listed current draw of approximately 7A, the pump is a modest load for most suitable 100Ah lithium auxiliary batteries. Total electrical demand from the rest of the vehicle or caravan should still be considered.

Will it work with AGM?

Yes. A healthy 12V AGM auxiliary battery can operate the pump when the circuit is wired and protected correctly.

How much battery will it actually use?

Water pumps typically operate only while water is being used, so daily energy consumption is often relatively small. Even at 7A, ten minutes of actual pump runtime would represent only around 1.2Ah of battery capacity.

Why does current draw increase when pressure increases?

The motor has to work harder as the pump operates against greater system pressure. The supplied data rises from approximately 3.9A at open flow to 7A at the 55 PSI shut-off point.

Is this actually an 11.3LPM pump?

The product is identified as an 11.3LPM model, but the supplied performance chart lists 10.80LPM at open flow. For practical system design, the pressure-versus-flow figures are more useful because real installations never operate at completely unrestricted open flow.

Will I get 11.3LPM from my shower?

No assumption should be made that maximum open flow will be available through a shower. Flow drops as pressure and plumbing resistance increase. For example, the supplied data lists approximately 6LPM at 30 PSI.

Can I install a water filter before or after this pump?

Potentially, but filters create additional restriction and must be rated for the system pressure. Excessive inlet restriction can also affect pump performance, so the filter and plumbing layout should be selected appropriately.

Can I use this pump on a boat?

Yes, it is suitable for compatible marine fresh water applications when installed using appropriate marine plumbing and electrical practices.

Would this suit a camper trailer with a kitchen and external shower?

Yes. That type of setup is a strong application for a pump with this level of flow and pressure, especially compared with a smaller single-outlet pump.

Is 55 PSI too much for caravan plumbing?

That depends on the plumbing components used. The pump's maximum listed pressure is 55 PSI, so hoses, fittings, filters, taps and appliances should all be checked to ensure they are suitable for the operating pressure.

What should I check before buying?

Confirm how many outlets you intend to operate, whether you need shower-level flow, check that your plumbing components are suitable for pressures up to the pump's listed 55 PSI shut-off point and make sure your 12V electrical circuit can handle up to approximately 7A plus any other simultaneous loads.

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💧 MORE FLOW. MORE PRESSURE. BETTER 12V WATER DELIVERY.

The SEAFLO 42 Series is a strong choice for travellers who need more than a basic sink pump but still want a compact and efficient 12V solution.

With self-priming operation, continuous-duty capability, dry-run protection, internal bypass technology and pressure capability up to 55 PSI, it is well suited to caravan, camper, marine and 4WD fresh water systems where dependable flow matters.

For customers running a sink, shower or multiple water outlets and looking for a capable upgrade over a smaller fresh water pump, the SEAFLO 42 Series provides a versatile balance of performance, size and electrical efficiency.