Your watermaker's running hours are the single most useful number for knowing when to service it. Track them correctly and you will change consumables at the right time, catch problems early, and avoid the only kind of failure that is genuinely expensive: a fouled membrane. Both the LEDI Scout and the LEDI Nomad have a built-in hour meter installed internally, so the number is always right there when you need it.
Why Running Hours Matter More Than Calendar Time
A watermaker that ran for two weeks solid in the tropics has been through far more stress than one that sat on a shelf for a year with the occasional one-hour run. Calendar time tells you very little. Running hours tell you how much work the pump has done, how loaded the pre-filter is, and roughly how close you are to a scheduled service. Every maintenance interval for a watermaker, from a pre-filter swap to a pump service kit, is properly expressed in hours of use, not months on a calendar.
What the Built-In Hour Meter Shows You
The hour meter on both the Scout and the Nomad accumulates total run time from the moment the high-pressure pump starts. It does not reset, which is intentional. A non-resettable counter gives you an accurate lifetime reading and, when you buy a second-hand unit, lets you verify the real history of the machine. LEDI's service team uses this figure when you call in for advice or send the unit to the Gold Coast for a service. It is the first thing they will ask for.
Pre-Filter: The Most Time-Sensitive Consumable
The pre-filter is the routine consumable in every LEDI system, and running hours are exactly how you know when to change it. As a general guide:
- Clean offshore water: replace roughly every 30 to 40 hours of run time.
- Dirty, silty, or estuarine water: replace roughly every 10 to 20 hours, sometimes sooner.
- In any conditions: change it immediately if feed pressure climbs noticeably or product output drops, regardless of hours.
The Scout uses a standard 5 micron 2.5"x5" cartridge, available from LEDI as a 2.5 x 5" pre-filter cartridge for $25 AUD. If you want longer intervals between changes, the Scout is also compatible with an add-on 2.5"x10" housing and the matching 2.5 x 10" filter cartridge at $20 AUD, which holds more dirt and gives the membrane cleaner feed water. That larger housing is included in the Watermaker Install Kit or can be added separately. A blocked pre-filter is not just an inconvenience: it starves the high-pressure pump of feed water and puts genuine strain on it. Checking at the correct hour intervals is cheap insurance.
The RO Membrane: Not a Routine Consumable
Unlike the pre-filter, the RO membrane is not something you replace on a fixed schedule. A well-maintained membrane lasts several years. What wears it out prematurely is consistently dirty feed water getting through a neglected pre-filter, running without flushing after use, or improper storage without pickling. If you are changing your pre-filter at the right hour intervals and flushing with fresh water after every session, the membrane should give you a long service life. When output genuinely falls or TDS climbs above acceptable levels, that is the signal to inspect and potentially replace it. A seawater RO membrane is $330 AUD and the swap is straightforward. For more detail on extending membrane life, see Watermaker Membrane Lifespan: What Shortens It and How to Make Yours Last for Years.
Pump Service Intervals
The Scout runs a Pumptec 107SS high-pressure pump (USA-made, 316 stainless, rated to around 800 PSI). The Nomad uses a Cat Pumps 2SFSEEL direct-drive plunger pump. Both are commercial-grade and fully serviceable. LEDI offers a Pumptec Service Kit for the Scout pump at $248 AUD. Your running-hour total is the key input for knowing when that service is due. The LEDI team can advise on the correct interval for your operating conditions when you call or email, and your hour meter reading is what they will use to give you an accurate answer rather than a conservative guess.
Keeping a Simple Log
The hour meter does the counting, but a short written or digital log adds context the meter cannot: what conditions you ran in, what the TDS reading was, when you changed the pre-filter, and when you last flushed or pickled. Fifteen seconds of notes after each session means you can see patterns. If output is slightly down, you can check whether you are running in warmer water (which raises output), cooler water (which lowers it slightly), or whether the pre-filter is getting close. A TDS reading alongside the hours gives you a trend line. The Nomad includes a TDS monitor and flow meter on its integrated control panel as standard. For the Scout, a separate inline TDS sensor at $69 AUD lets you do the same. Find out more about what to measure and why in Ensuring Safe Drinking Water: A Guide to Water Testing.
Using Hours to Plan Around Your Trip
If you know a passage or an overland trip will take roughly 30 days and you expect to run the watermaker for around two hours a day, that is approximately 60 hours of run time. You can work out in advance whether you need an extra pre-filter cartridge, whether the pump service is due before you leave, and whether the membrane needs inspecting. Running out of pre-filters in a remote anchorage is an avoidable problem. Spare parts and consumables ship from the Gold Coast Australia-wide and internationally, usually within one business day, but having a spare or two on board before you leave is always the simpler option. For a full run-through of the ongoing costs involved, see The True Cost of Owning and Maintaining a LEDI Scout Watermaker.
Frequently Asked Questions
How often should I change the pre-filter on my LEDI Scout?
In clean offshore seawater, aim for every 30 to 40 running hours. In silty, dirty, or estuarine water, change it every 10 to 20 hours, or sooner if feed pressure rises or output drops. The hour meter on the Scout makes it easy to track this accurately.
Does the hour meter reset when the unit is serviced?
No. The hour meter on LEDI units is non-resettable by design. It shows lifetime running hours, which lets LEDI's service team assess the unit's history and give you accurate service advice.
How do I know if my RO membrane needs replacing?
A genuine drop in output or a sustained rise in TDS (above roughly 800 ppm) are the main signals. The membrane is not a routine consumable and can last several years with proper care, including regular pre-filter changes, freshwater flushing after use, and correct pickling for storage. Running hours on their own do not indicate when a membrane needs replacing; performance does.
What running-hour data should I have ready before contacting LEDI for service advice?
The total hours on the built-in meter, your most recent TDS reading if you have one, and a brief note on the water conditions you have been running in (offshore, estuarine, silty). That gives the team enough to advise you accurately without guesswork. You can reach LEDI at info@ledi.com.au or on +61 494 562 668.
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