What the Pumptec 107SS Actually Is
The Pumptec 107SS is a small-scale, direct-drive high-pressure plunger pump designed for continuous-duty 12V DC operation. It runs on 12V at 16 to 18 amps, which puts it squarely within what a standard marine house battery bank can deliver without a generator or inverter. The pump body and wetted parts are 316 stainless steel, the same grade used throughout commercial marine installations. It is manufactured in the USA and is a fully serviceable, non-proprietary unit, meaning parts, seals and service kits are available worldwide, not just from LEDI.
In the Scout, the 107SS reaches roughly 800 PSI of working pressure, which is sufficient to push seawater at up to 35,000 ppm TDS across the RO membrane and produce output consistently under 800 ppm TDS, typically in the 250 to 300 ppm range. That is well within Australian drinking water standards, and the built-in UV steriliser provides a further treatment stage before the water reaches your tank.
Pros of a Small 12V Plunger Pump
Running a high-pressure RO system from 12V DC is not a given. Most fixed watermakers use AC-powered pumps or large 24V setups. The Pumptec 107SS makes solar-friendly, off-grid operation genuinely practical. Here is what it gets right:
- No generator needed. At 16 to 18A on 12V, the Scout runs comfortably from a house battery bank backed by 200 to 400W of solar. For a cruising sailor anchored in calm water with panels in the sun, the system is essentially free to run.
- Compact and light. The 107SS is small enough to package inside the Scout's carry case at a total system weight of 18 kg, single-person carry, no installation, no plumbing. Drop the submersible feed pump over the side, connect the hoses, and you are making water in minutes.
- Fully serviceable. The pump uses standard seals and components. A Pumptec Service Kit is stocked by LEDI and contains everything needed for a rebuild. If a seal fails at sea, you are not waiting for a proprietary part from a single supplier.
- 316 stainless construction. Every part in contact with pressurised seawater is 316 stainless. This is the same material specification used in fixed commercial marine watermakers costing far more.
- Consistent pressure at RO-rated PSI. Unlike diaphragm pumps, which can struggle to maintain stable pressure, a plunger pump delivers consistent, repeatable pressure at the membrane, critical for reliable salt rejection.
- Hour meter included. The Scout has an internal hour meter that tracks running hours, so you know exactly when the pump and pre-filter are due for service. No guessing.
The Honest Trade-Offs
A small 12V pump is not the right choice for every situation. It is worth being direct about what the 107SS does not do:
- Output is limited by design. The Scout produces 10 or 20 litres per hour depending on the configuration. For a couple on a trailer sailer or small cruiser, that is plenty. For a crew of six on a charter passage, it probably is not. That is a job for the LEDI Nomad, which runs a Cat Pumps 2SFSEEL and produces 40, 60, or 80 LPH.
- Amp draw is real. 16 to 18A at 12V is about 200W continuous. In overcast conditions or with a small solar array, you will need to plan your run times around battery state. It is not a problem most sailors cannot manage, but it is not something to ignore either.
- It is not self-priming at the high-pressure stage. The Scout ships with a separate submersible feed pump that supplies water to the Pumptec under positive pressure. The submersible feed pump does the priming work; the 107SS handles the high-pressure side. This is the correct engineering approach, forcing a high-pressure plunger pump to self-prime against atmosphere is hard on seals, but it does mean you have two pumps to look after, not one.
- Noise. The system runs at around 65 dB, comparable to a dishwasher. Not silent, but not intrusive on a boat where you are used to engine and wind noise.
- Less efficient per litre than some high-end systems. Larger, energy-recovery-equipped commercial watermakers squeeze more litres per kilowatt-hour. The 107SS does not have energy recovery. The trade-off is simplicity, serviceability, and a price point that is a fraction of a fixed installation.
Feed Pump Setup: How It Works with the 107SS
One thing worth understanding clearly: the Pumptec 107SS handles the high-pressure side of the seawater desalination reverse osmosis process. It does not pull its own feed water from the sea. The Scout ships with a separate submersible feed pump on a 5 m hose, which you drop over the side (or connect to a seacock) and plug into the Scout's SP13 2-pin socket. That pump delivers water to the pre-filter and then to the Pumptec inlet under gentle positive pressure.
For most applications, the standard 5 m hose covers the distance. If you need more reach, the Scout Auxiliary Feed Pump suits moderate runs, and the Nomad Auxiliary Feed Pump handles longer runs of roughly 20 to 30 m horizontally and up to 5 m of vertical lift. Both use the same SP13 2-pin connector, so either plugs straight in with no adapter.
Pre-Filtration: Protecting the 107SS
The Pumptec 107SS is a precision pump. Silt, debris or biological matter that reaches the plunger will shorten seal life. That is why the Scout's pre-filter stage matters, it is the first line of defence, and replacing it on schedule is the single most important routine maintenance task.
The standard Scout pre-filter is a 2.5 x 5" cartridge rated at 5 micron. In clean ocean water, replace it every 30 to 40 running hours. In silty or turbid conditions, that interval drops to 10 to 20 hours, or sooner if feed pressure climbs or output drops. The cartridge is a $25 swap, cheap and fast. The Scout is also compatible with a larger 2.5 x 10" cartridge, which holds more dirt between changes and gives the 107SS cleaner feed water. This is included in the Watermaker Install Kit or available separately.
Keeping the pre-filter fresh protects the pump seals and the RO membrane. The membrane is not a routine consumable, with proper flushing and pickling it lasts several years, but dirty feed water is one of the fastest ways to shorten its life.
When to Replace the Pump vs Service It
The 107SS is a wear item, not a consumable. With regular pre-filter changes, freshwater flushing after each use, and proper membrane pickling during storage, the pump runs for thousands of hours before needing attention. When it does need work, a Pumptec Service Kit at $248 covers a full seal and valve rebuild. If the pump body itself reaches end of life, a replacement Pumptec 107SS is available directly from LEDI at $1,550.
LEDI's Gold Coast workshop handles in-house servicing for the life of the unit, and wear parts post Australia-wide and internationally, typically within one business day. You are not locked into a dealer network or a manufacturer's service centre overseas.
Who Should Choose a 107SS-Based System
The Pumptec 107SS in the LEDI Scout is the right pump for:
- Sailors on yachts from roughly 20 to 50 ft who want portable, no-install water independence.
- Couples or small crews who need 10 to 20 LPH and want to run entirely on solar with no generator.
- 4WD and overland travellers who need to make water from rivers, dams or coastal sources without a fixed installation.
- Owners of smaller catamarans or trailer sailers who cannot justify a fixed install but want genuine offshore capability.
If your daily demand is higher, showers underway, larger crew, liveaboard use, charter, the 107SS will not keep up. The Nomad, with its Cat Pumps plunger and 40 to 80 LPH output, is the right unit for that load. The team can help you size correctly if you are unsure: contact LEDI at info@ledi.com.au or on +61 494 562 668.
The LEDI Scout starts at $4,899 AUD for the 10 LPH version and $5,799 for the 20 LPH, built on the Gold Coast and shipped direct. Spare parts, service kits and consumables are all available from the LEDI spares store.
Frequently Asked Questions
Why does the Scout use a plunger pump rather than a diaphragm pump?
Plunger pumps deliver stable, consistent pressure at the high PSI levels needed for seawater RO. Diaphragm pumps are better suited to low-pressure feed or transfer duties. The Pumptec 107SS produces around 800 PSI reliably, which is what forces seawater across the membrane with a 99.4% salt rejection rate.
Can I service the Pumptec 107SS myself?
Yes. The pump is fully serviceable with standard tools. LEDI stocks a Pumptec Service Kit with the seals and valves needed for a rebuild. For anyone who has done basic mechanical work, it is a straightforward job. LEDI's Gold Coast workshop is also available for in-house servicing.
How many running hours does the Pumptec 107SS last?
Pump life depends heavily on pre-filter maintenance and water quality. With clean feed water, regular pre-filter changes, and freshwater flushing after each session, the pump runs for thousands of hours before requiring a rebuild. The Scout's internal hour meter makes it easy to track usage and stay on schedule.
What happens if the pump fails offshore?
The Pumptec 107SS uses standard, non-proprietary parts available from marine and industrial suppliers worldwide. A service kit covers most failure modes. LEDI also posts spare parts internationally, typically within one business day from the Gold Coast. For more on keeping your system running, see our guide on marine watermaker maintenance and tracking watermaker running hours.
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