Re: Water maker Questions


I suggest that you need to back up some from your assumptions and take a different approach. First of all, if you pay £500, for SW302521 Filmtec membranes, you are definitely overpaying. They should be about $200USD plus VAT/Freight. There is one membrane manufacturer in the world, so it makes no difference where you buy membranes.

Allow me to make a few points:
  • Your Dessalator watermaker is probably 17 years old if it is as old as the SM. Most other brands do not last that long. Dessalator is a modular design which means modules can be replaced or overhauled.
  • There can be other causes for a water maker not working. Membrane tube seals could be one of them. 
  • If there is a membrane failure, it may be only one of them.
  • When a watermaker has been neglected and not used, you should allow it to run for at least 30 minutes, discarding all product water before testing.
  • Membranes require moisture. If a membrane is allowed to dry, it will probably never work again.
  • Some water maker manufacturers promise a lot and deliver very little. Dessalator is not one of these manufacturers.
I suggest that once you put the Dessalator water maker in good working condition that you religiously do the following:
  1. Rinse the membranes weekly following the instruction, or run the watermaker every 3 days.
  2. If you do not have a method of discarding produced water from the watermaker, add a 3-way valve to do this.
  3. Before you add any water to the tank, test it. You will find that the TDS will decrease as the watermaker run increases, usually allowing 300TDS or less after 5 minutes.
I hope this helps you.

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
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On Sat, Sep 5, 2020 at 1:31 AM Mark Barter <markbarter100@...> wrote:

This is a really useful thread. 

Nunky is fitted with a Dessalator D100. We assumed that the green light meant it was working well. When it became apparent that it wasn’t we had a tank full of brine. I now know that the green light means nothing. I actually tested the output against sea water and somehow it was worse.

I have no idea when the water maker was last used but my guess is months and months before we bought the boat. Due to various issues including Covid we were then away from the boat for months. I didn’t know about pickling and regular flushing at that stage so it’s hardly surprising that the water maker isn’t working properly.

I am going to clean the membranes to see if that helps but if it doesn’t it’s either 3 new membranes at £500 each or a new system with proper quality control. 

Has anybody managed to successfully resurrect a system from this state? If so, how?

Mark & Nicky Barter
S/V Nunky
SM 110

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