Re: Dessalator 230v 160 LPH watermaker fault

Porter McRoberts

Dear Dan,

Agree with both suggestions.  
Either the HP sensor is the issue, or the board believes it does not reach adequate high pressure. Agree with placing needle dead in the green to high within the cutout time period. Also unscrewing the sending wire from the HP sensor. But since the HP pressure sensor works in micro current, unscrew cap, paint in some Corosion X and reseat cap. The sensor may be on its way out, but at least you will get all the amperage you can from it, until it fails completely down the line. 

The watermaker I’m sure as you know is a very simple process made complex by the sensing, and for good reason, a drop in pressure in the ER is very bad. In water makers. And patients. 

Beat of luck Dan!

Porter McRoberts 
S/V IBIS A54-152 (160-230v Dessalator)
WhatsApp:+1 754 265 2206

On Nov 11, 2020, at 7:01 AM, Mohammad Shirloo <mshirloo@...> wrote:

Hello Dan;


We have the same water maker aboard Kokomo. However, I’m not sure if it is the same or a later design. Going through your procedure, I have one recommendation. I see that you state that you increase the high pressure until you are just below the green zone on your HP gauge. The system will go into a fault status and stop, if the pressure does not pass a certain threshold within a certain amount of time  after the HP pump kicks on. I do not know what these thresholds are or how they are measured.  Also, in talking to Dessalator support, Martin Dee Jong, on several issues over the years, he has always recommended to keep the pressure of the HP pump on the high side of green, just shy of the red zone. He stated the reasoning as the unit is very capable of handling this pressure setting 24x7x365 and there is no reason to lower the pressure and reduce the amount if water being produced. We have followed this advice for the past 5 years and currently have over 600 hours on our original 11 year old membranes that still put out water in the 250 PPM range. As a side note, he also stated that there’s no need to back flush, as long as you are producing water at least once a week, which we always do, when on board.


I would recommend trying to increase the HP pump setting in the mid to upper range of the green zone. It may be that the sensitivity of the sensors that gauge the pressure and time may have changed over time.


Happy Sailing;



Mohammad and Aty

B&B Kokomo

AMEL 54 #099


From: <> On Behalf Of Dan Carlson via
Sent: Wednesday, November 11, 2020 8:34 AM
Subject: [AmelYachtOwners] Desallator 230v 160 LPH watermaker fault


Good morning all,   On sv BeBe, SM#387,  I have the original Dessalator 230v 160LPH water-maker. 

Today was the first time I this season that I have tried to run the water maker (as we were in the muddy Chesapeake Bay with  ready access to decent city water..).  The membranes had been auto-flushed with fresh water for 2 minutes, twice per week while away and I had tested that both the low and HP pumps were functional through the initial start-up sequence. 

I started up the water-maker according to procedure with the pressure control valve initially all the way anti-clockwise (no pressure) and the  product water diverted to a sink faucet.   The low pressure pump kicked on and the low pressure gauge read the typical 12 o-clock reading.  After the typical delay the high pressure pump kicked on and the low pressure guage dropped slightly to about 10:30 (as typical).   After the "green" light came on I began to very slowly increase the pressure with the needle valve.   I stopped when I just reached just below the green zone on the HP gauge and product water began to come out of the faucet.   During this time the product quality lights had gone from green to amber when water began to flow and then back to green after a few seconds of product flow.   I began my usual 30 second count after the product quality light turns green before sampling and testing the water quality with my tongue and TDS meter, before I would then divert the water to the fresh water tank.  All during this time I was watching both the high and low pressure gauges for any fluctuation and none was seen.  I had given the water a taste test and was about to pull the sample for the TDS check when the water-maker shut down with the red "alarm" light.  I turned off the water-maker switch, and the 230v breaker, re-set the pressure control valve, and  checked for any obvious leaks or ? in the engine room.   After those checks I went through the same sequence and had the exact same shutdown approximately 30 seconds after the water quality light went back to green.   On the third try when I turned the water-maker switch back on it went directly to alarm mode. 

After searching the Amel Desallator manuals on-board, and searching this forum I also performed the following troubleshooting: 
1) removed the panel in the locker and checked for any noticeable corrosion, 
2) I checked the fuse in the Desallator control box and it was tight and did not appear to be blown, 
3) checked for any tripped breakers or appearance of any burning around the relays,
3) I checked for any corrosion around the TDS probe and it appeared in good condition. 
4) There is a reference in the Desallator manual to an adjustment screw on the HP switch but neither of the switches in the manual resembled the switch on the back of the panel.   There is a screw in the back of this switch and I made a small attempt to turn it but did not force any movement.  (Picture attached)  Does anyone know if this HP Switch can be adjusted?   Or if it is recommended to remove it and possible clean it out?   Or further tests. 

- At this point I believe that the indications are that there is probably an issue with the HP Switch, but I would like confirmation from others or suggestions of other troubleshooting steps.   
- are there further steps to  either adjust the HP switch or clean the HP switch? 
- In the forum there were comments that owners had disconnected and run the water-maker without the HP switch in the circuit, but I would also like a little more confirmation and advice on how to go about this before taking this next step.   
- Also, at this stage when I turn the water-maker on it goes directly to the Alarm state.  Is there a re-set button that I have not found? or is that indicative of a failed HP switch. 

As background:  twice last season I did have the water-maker shutdown in a similar manner.  Once after it has been running some time (45 minutes? ) and another time shortly after start-up.   In neither case was I immediately attending to the water-maker and it subsequently re-started with no issues and no root cause found at the time. 

Thanks and regards,  Daniel and Lori Carlson on sv BeBe, SM #387

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