Par-Max 1 PLUS 12V Fresh Water Pump | 3.8LPM 35PSI

💧 JABSCO PAR-MAX 1 PLUS 12V FRESH WATER PUMP – 3.8LPM AUTOMATIC PRESSURE PUMP

Compact Self-Priming 12V Water Pump for Caravans, RVs, Boats & Small Fresh Water Systems

💦 The Jabsco Par-Max 1 PLUS is a compact 12V automatic fresh water pressure pump designed for smaller boats, caravans, RVs and portable water systems where dependable pressure and low water demand are required.

Delivering up to 3.8 litres per minute at open flow and operating at pressures up to 35 PSI, the Par-Max 1 PLUS is ideal for single-tap and low-flow applications where a larger water pump would be unnecessary.

The diaphragm pump is self-priming up to 1.8 metres and incorporates an automatic pressure switch, allowing the pump to start when a tap is opened and stop automatically once the tap is closed and system pressure is restored.

With vibration-reducing rubber mounts, thermal overload protection, quick-connect plumbing ports and compatibility with both 10mm and 12mm hose using the supplied adaptors, the Par-Max 1 PLUS is designed to make compact fresh water installations simple and reliable.

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⚡ KEY FEATURES

💧 3.8LPM Fresh Water Flow
Provides up to 3.8 litres per minute / 1.0 gallon per minute at open flow, making it well suited to smaller water systems.

🚰 Automatic Pressure Switch
Starts the pump automatically when water is demanded and stops it when the tap is closed and pressure returns.

📈 Up to 35 PSI
Provides useful pressure for compact sink, basin and small fresh water applications.

💦 Self-Priming to 1.8 Metres
Can draw water from a tank positioned below the pump when installed within the stated priming limit.

🔇 Reduced Noise & Vibration
Rubber mounting feet help isolate pump vibration from the surrounding structure.

🌡️ Thermal Overload Protection
Built-in protection helps safeguard the motor if operating temperature becomes excessive.

🔧 Quick-Connect Plumbing Ports
Plug-in ports simplify installation, maintenance and pump removal.

🚿 10mm & 12mm Hose Compatibility
Ports suit 10mm / 3/8" hose and adaptors are included for 12mm / 1/2" hose.

⚡ Low Electrical Demand
Designed as a low-current pump for battery-powered fresh water systems.

🛡️ Durable Pump Construction
Features a reinforced polypropylene housing, Santoprene diaphragm, EPDM valves and 316 stainless steel check-valve spring.

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🚐 IDEAL FOR SMALL CARAVAN & RV WATER SYSTEMS

The Par-Max 1 PLUS is designed for applications where you need automatic water pressure but don't require the high flow of a larger multi-fixture pump.

Typical applications include:

• 🚰 Caravan sinks
• 🚐 Small RV fresh water systems
• 🚤 Boat sinks and freshwater outlets
• 🏕️ Camper trailer kitchens
• 🚙 4WD water systems
• 💧 Portable freshwater installations

For one small outlet or a simple low-flow plumbing system, its 3.8LPM capacity can provide useful pressure without installing a much larger pump than the system actually needs.

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⚙️ AUTOMATIC ON-DEMAND OPERATION

The built-in pressure switch allows the Par-Max 1 PLUS to function as an automatic demand pump.

When a tap is opened, plumbing pressure falls and the pump starts automatically.

When the tap is closed, pressure rises until the pump reaches its shut-off point and switches off.

This means you do not need to manually switch the pump on and off every time you want to use water.

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💦 SELF-PRIMING TO 1.8 METRES

The Jabsco Par-Max 1 PLUS is capable of self-priming to approximately 1.8 metres / 6 feet.

This gives considerably more installation flexibility than a non-self-priming centrifugal transfer pump.

The pump can therefore be mounted above the water tank within its stated priming limits rather than needing to remain submerged or gravity fed.

⚠️ Suction hose length, fittings, leaks and restrictions can affect priming performance. Keep the inlet plumbing as airtight and unrestricted as practical.

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📈 UP TO 35 PSI WATER PRESSURE

The pump operates at pressures up to approximately 35 PSI.

This makes it suitable for compact freshwater systems where useful tap pressure is required without the higher shut-off pressures associated with larger pumps.

⚠️ Always confirm that hoses, filters, fittings and taps in the water system are suitable for the pump's operating pressure.

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🔇 QUIETER, SMOOTHER INSTALLATION

Water pump vibration can easily transfer into caravan floors, cabinetry and boat structures, creating more noise than the pump itself.

The Par-Max 1 PLUS uses rubber mountings designed to reduce vibration transmission into the surrounding installation.

For best results, mounting the pump securely while avoiding rigid plumbing immediately beside it can further help minimise vibration and noise.

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🌡️ BUILT-IN THERMAL OVERLOAD PROTECTION

The pump incorporates thermal overload protection to help protect the motor if operating temperature becomes excessive.

This adds another layer of protection for installations where the pump may be used frequently or located in a warmer compartment.

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🌡️ LIQUID TEMPERATURE RANGE

The Par-Max 1 PLUS is specified for pumping liquids from approximately 4°C up to 43°C maximum.

This makes it suitable for normal fresh water applications within that temperature range.

⚠️ Do not use the pump with liquids hotter than the stated 43°C maximum unless specifically approved by Jabsco.

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🔧 QUICK-CONNECT PLUMBING

Quick-connect / disconnect ports make plumbing installation and servicing easier.

The standard ports suit 10mm / 3/8" hose, while adaptors are supplied to suit 12mm / 1/2" hose.

This gives installers useful flexibility when integrating the pump into existing caravan, RV or marine plumbing.

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🛡️ DURABLE INTERNAL COMPONENTS

The Par-Max 1 PLUS uses materials selected for reliable fresh water pumping applications:

• 🛡️ Reinforced polypropylene pump housing
• 💧 Santoprene diaphragm
• 🔄 EPDM valves
• 🔩 316 stainless steel check-valve spring

These components contribute to the pump's durability in compact caravan and marine fresh water systems.

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⚡ LOW-CURRENT 12V OPERATION

The Par-Max 1 PLUS is described as having a low electrical draw, making it suitable for battery-powered applications.

Because a fresh water pump normally operates only while water is being used, its overall daily energy consumption can remain relatively small in most caravan and touring systems.

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📋 TECHNICAL SPECIFICATIONS

Brand: Jabsco

Model: Par-Max 1 PLUS

Product Type: Automatic Fresh Water Pressure Pump

Power Supply: 12V DC

Pump Type: Diaphragm

Maximum Open Flow: 3.8LPM / 1.0GPM

Maximum Operating Pressure: Up to 35 PSI

Automatic Pressure Switch: Yes

Self-Priming: Yes

Maximum Self-Priming Height: 1.8 Metres / 6 Feet

Liquid Temperature Range: Approximately 4°C–43°C

Thermal Overload Protection: Yes

Mounting: Vibration & Noise Reducing Rubber Mounts

Ports: Quick Connect / Disconnect

Standard Hose Connection: 10mm / 3/8"

Included Adaptors: 12mm / 1/2"

Housing: Reinforced Polypropylene

Diaphragm: Santoprene

Valves: EPDM

Check Valve Spring: 316 Stainless Steel

Applications: Small Boats, Caravans, RVs & Compact Fresh Water Systems

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🔧 INSTALLATION CONSIDERATIONS

• Use a suitable 12V DC power supply
• Mount the pump securely using the vibration-isolating mounts
• Keep inlet plumbing airtight to maintain reliable self-priming
• Use suitable freshwater-rated hose and fittings
• Use the correct 10mm connection or supplied 12mm adaptors
• Confirm fuse and electrical cable requirements before installation
• Ensure all plumbing components are rated for up to 35 PSI
• Keep the pump within its stated 4°C–43°C liquid temperature range
• Check all hose connections carefully for leaks after installation

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❓ FREQUENTLY ASKED QUESTIONS

Is this a good pump for a caravan sink?

Yes. A single caravan sink is one of the strongest applications for a compact 3.8LPM automatic pump. It provides useful water pressure without fitting a larger high-flow pump that may be unnecessary for a simple system.

Would this be suitable for a caravan with only one tap?

Yes. The Par-Max 1 PLUS is particularly well suited to small fresh water systems with one primary outlet.

Can I use it for two taps?

Potentially, but the available 3.8LPM maximum flow would be shared between both outlets if they are opened at the same time. It is best suited to smaller systems where simultaneous high flow is not required.

Would you recommend it for a shower?

It may operate a very low-flow shower head, but 3.8LPM is modest compared with larger caravan shower pumps. If strong shower performance is important, a higher-flow pump would generally be the better choice.

How does this compare with the SEAFLO 21 Series 3.8LPM pump?

Both are compact low-flow automatic water pumps intended for smaller systems. The Jabsco provides a stated 3.8LPM open flow, up to 35 PSI, self-priming to 1.8 metres, quick-connect ports and thermal overload protection. The better choice will depend on your plumbing layout, preferred fittings and installation requirements.

How does it compare with an 11LPM-class pump?

The Par-Max 1 PLUS is much better suited to a small sink or single-outlet installation. An 11LPM-class pump makes more sense where you want stronger shower performance or need to supply several fixtures. A larger pump may also use more water and electrical power than necessary in a very small system.

Will it automatically start when I open the tap?

Yes. The integrated pressure switch provides automatic on-demand operation. Opening a tap causes the pump to start, and closing the tap allows it to build pressure and switch itself off.

Do I need a separate pressure switch?

No. The pressure-switch function is built into the pump.

Do I need to turn the pump switch on every time I use the tap?

You would normally leave the pump's main electrical circuit enabled while the water system is in use. The internal pressure switch then handles normal starting and stopping automatically as the tap is opened and closed.

Can I mount the pump above my water tank?

Yes, within its installation limits. The Par-Max 1 PLUS is self-priming to approximately 1.8 metres, allowing it to draw water from a tank mounted below the pump.

Is the 1.8m self-priming rating vertical lift or hose length?

It refers to the pump's stated self-priming lift capability rather than simply the total hose length. Long hose runs, fittings, air leaks and restrictions can still reduce actual priming performance.

Will I need a one-way valve?

The pump already incorporates a check-valve arrangement as part of its design. Whether any additional valve is needed depends on the final plumbing configuration and should not be assumed for every installation.

Can I use it with a water filter?

Yes, provided the filter is suitable for fresh water use and does not create excessive restriction. Filters should also be rated for the system pressure.

Do I need an accumulator tank?

An accumulator tank is not listed as a requirement for operation. In some systems an accumulator may still help smooth flow and reduce cycling, but whether one is worthwhile depends on the plumbing configuration and how the pump behaves with your particular tap or outlet.

Will it work from a lithium battery?

Yes. The pump operates from 12V DC and can be used with a suitable 12V lithium auxiliary system when correctly wired and protected.

Will it work from an AGM battery?

Yes. A healthy 12V AGM battery is also suitable for powering the pump.

How much battery power does it use?

The pump is described as having low current draw, but a specific amperage is not provided here. Because a small fresh water pump usually runs only for short periods while a tap is open, total daily battery usage is generally modest.

Does it run continuously or only when water is required?

In a normal pressure-water installation it operates on demand. The pump starts when system pressure drops and switches off again when pressure is restored.

What happens if the pump gets too hot?

The pump includes built-in thermal overload protection. This helps protect the motor if excessive temperature is detected, although the cause of overheating should still be investigated rather than relying on the protection system repeatedly.

Can I pump hot water through it?

The stated liquid temperature range is approximately 4°C to 43°C. It should not be used with water hotter than 43°C unless Jabsco specifically approves the application.

Will 35 PSI damage my caravan plumbing?

That depends on the hose, filters, fittings and taps used. The entire system should be checked to ensure all components are rated for the pump's operating pressure.

Does it come with fittings for 12mm caravan hose?

Yes. The standard ports suit 10mm / 3/8" hose and adaptors are provided for 12mm / 1/2" hose.

Is it easy to remove for servicing?

The quick-connect / disconnect plumbing ports are designed to simplify pump removal compared with permanently threaded plumbing connections.

Is it suitable for a boat?

Yes. The Par-Max 1 PLUS is designed for fresh water applications on small boats as well as caravans and RVs.

Would this make a good replacement for an old small caravan pump?

Potentially. Compare your existing pump's voltage, flow, pressure, hose connections, mounting space and electrical requirements. If your current system only operates one small outlet, the 3.8LPM Par-Max 1 PLUS can be a practical replacement option.

What should I check before buying?

Confirm that 3.8LPM provides enough flow for your intended outlet, check whether your plumbing is 10mm or 12mm, make sure all components are rated for up to 35 PSI and verify the current electrical requirements if you are replacing an existing pump or designing a new circuit.

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💧 COMPACT JABSCO WATER PRESSURE FOR SMALL 12V SYSTEMS

The Jabsco Par-Max 1 PLUS is a practical choice when you need dependable automatic fresh water pressure without the size and flow of a larger multi-outlet pump.

With up to 3.8LPM flow, 35 PSI pressure capability, self-priming to 1.8 metres, vibration-reducing mounts, thermal overload protection and quick-connect plumbing, it delivers the essential features needed for compact caravan, RV and marine fresh water systems.

For a small sink, single water outlet or low-demand touring setup, the Par-Max 1 PLUS provides a compact and proven approach to automatic 12V water delivery.