Five Year Old Watermaker – How Is It Doing

We are on our first “passage” from Poole to Plymouth in the UK. While short, it is giving us a chance to run up some of the systems and electronics. In particular we wanted to test our five year old Village Marine NF800 watermaker which has been in storage mode for eight months


Experience indicates that watermakers are not happy sitting around. Ideally, they get periodic flushes with fresh water if they are not being employed. During the first three years with this unit it was either used weekly or flushed with fresh water on a four to six week interval.

During the winter of 2008/9 Wind Horse was hauled for five months. At Village Marine’s suggestion, we pickled the watermaker in propylene glycol, a food grade preservative and anti-freeze agent (along with the rest of our plumbing).

This past winter we followed the same procedure, and after an unexpectedly long eight month absence were not sure what we’d find. Which brings us to today.

This is an 800 US gallon/3000 liter per day rated unit, or 126 liters/33 gallons an hour. Output varies with pressure, water salinity, and temperature. Our output in cool water (we don’t know the salinity) at 850PSI is an amazing 30 GPH, which corrected for water temperature puts us 15 to 20% over the original rating of these membranes and within a few points of where they were when new.

Given the age and lack of use we were assuming the membranes would require replacement. Looks like we’ve got a while to go.

Posted by Steve Dashew  (June 1, 2010)

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