Water Maker Update

Our Schenker Watermaker has been running perfectly for the last 4 months (touch wood). The unit is making 30 litres an hour at a water temperature of 23 degreec C.  I’m changing the pre filter every 4 days and cleaning it with sea water rinsing in freshwater then hanging it out to dry in the sun for four days. This way two filters last around two months.

The total cost per year for filters is around £60 plus cleaning chemicals and pickling chemicals this brings the total service cost to around £100 per year.

More news on the watermaker in due course.

Update on Watermaker issue

Have now been using the watermaker for a week or so and (touch wood) no problems. It’s running very well with no noise or screaching at all.

The machine is making 31.5 litres an hour with a water temperature of 19 degrees C.

Wach this space 🙂

Investigation Results

We had the following email from Jim McDonald early in October giving the details of his investigation:

“Just a short note to update you on your watermaker. I ran the machine for 10 hours and whilst it was working fine, producing good quality water, There was a squeeking noise from one side of the cycle.
I put both SC1 & SC2 Chemicals through the machine for 30 mins each and whilst it lessened it a bit, it was still there. I spoke with the Schenker factory who said that whilst it was not a common occurance, it has been known that machines can be noisy at times with the noise often disappearing. They said this would cause no harm to the machine. They stated how important it is that the prefilter is changed regularly and that every possibility must be made to ensure that no dirt is allowed to enter the watermaker.

I stripped down the machine and could find no debris inside although there was fouling to one of the pistons.

There were also some very small scratches on both the top and bottom rods. This would suggest that at some time some debris has passed through the watermaker. They were not deep enough to damage the machine. I also found that there were some marks on two of the seats on the non return valves. Whilst Im not sure that they would cause a problem, I have changed them. All the major o rings on both the top and bottom parts of the ERS have been changed as well.

I am now running the machine for a further 10 hours after which I will pickle it and leave it ready for collection. The noise has now gone and the machine is working normally.”

So this has hopefully solved the problem allthough the root cause has still not been found. The water goes through a 50 micron pre filter and then through a 5 micron sediment filter before it enters the machine. We change the filter every four days and wash it through and let it dry in the sun. Another washed filter takes its place. Once a month a new filter is added to the rotation. I am convinced that no debry can enter the sustem through the water and I am sure a 4 micron piece will not dammage the system as otherwise Schenker would have a smaller filter element.

We will put the Watermaker to use again next Spring. So we will see how it fairs.

Watermaker Aug 07 to Jul 08

The replacement Modular 30 arrived late July 07 and I fitted it under the bunk in the “utility” room as this would place the unit totally under water.  Previous location was above the waterline but only by about 400mm. The Schenker user manual suggest placing it below the waterline but it also said the pump would be fine to about 1 meter above.  The unit was started and it was run for three hours on average per day until Noveember 5th when we decided to winter in a Marina.

The unit was still not completely free of air but did not cut out as the other one did. It was making a screeching sound which sounded like air in the system  Jim suggested that this was indeed air and it would sort itself out in due course.  It did not do so up to the date we moved into the Marina.

Through the winter (Nov 5th to March 6th) we flushed the unit through with its in built flush system to stop any growth and smell building up over the winter. The unit was started again in March and run for 3 hours again per day. This is where the problems started again. The noise got worse and the unit started to run at a higher pressure just like the Smart 30. Again the blame went to the “air in the system” but all my attempts to remove this “air” did not work.

The unit still made water, around 26 litres on average per hour but it kept cutting out, resetting itself and was I must admit not very reliable. In May 08 the water started to taste salty so I emailed Jim McDonald again to get some advice. He suggested to leave the unit running for 10 minutes before switching it to tank. Well I thought this was a bit much, when it was running well it only needed 2 minutes and the water was fine. Anyway emails went back and for but no solution was found. Eventually with the noise getting worse and the cutting out happening more and more I had had enough. I removed the unit and checked every single hose connection. Nothing.  I then removed the pump unit and found a leak in the accumulator. This was clearly a manufacturers fault as the seal in the accumulator was not fitted correctly.

This I fixed and the unit was reconnected but no, the same faults where still there. I then took the watermaker unit out again and with the help of the supplied ERS (Energy Recovery System) maintenance booklet, I took the ERS apart. Well, no wonder it was making a noise and no wonder it was working above pressure. Two of the 12 ‘O’ rings where broken. Now surely Schenker should have recognised the symptoms but they did not. The unit was slowly but surely breaking the ‘O’ rings over the previous months and eventually it got so bad that it would not run properly at all.

I replaced the rings and refitted the unit.  It ran perfectly. 32 litres of water per hour at 5.6 bar. Perfect. I advised Jim of this and we agreed that I returned the unit for testing to the UK when we visited our family and friends in August.  Arriving at Schenkers in Weston Super Mare we explained again to Jim all the symptoms the unit was showing using photos and eve video. He said he would check with Schenker in Italy to see if any other units had ever had the same fault. Also he seemed to recall a unit he sold prior to ours having a similar ‘o’ ring fault.

We agreed that he would run the unit constantly for a Month while we were here and see how it fared. We left the unit with him so watch this space.

Watermaker June 07 to July 07

After two months navigating through the French Canal system we popped out in Port St Louise Du Rhone. After fitting the mast we motored out to the anchorage and with a water temperature of 17 degrees centigrade we started the watermaker. The Smart 30 made 25 litres of water per hour so we were very happy.

The water quality was excelent, very tasty sweet and cool.  The unit still had a bit of air in it which was difficult to remove but it seemed to be working fine.

The unit was in use from 6 June 2007 but only intermitantly as we were on our way to Greece via Corsica, Italy and Sicily and we managed to fill up at the odd Marina or two on the way as anchoring was not always possible.  We arrived in Greece on the 3rd July 2007 and the unit was then used every day for three hours.

Here the problems started. The trapped air was imposibble to get out and it started working at an increased pressure. Normaly it should run at around 6 bar but it was going up to 8 bar and sometimes higher (9 bar) it would then cut out as the pressure switch is set to around 8.5 bar. I spent many hours in our “utility” room trying to sort it out.

I had to admit defeat and contacted Jim McDonald from Schenker in the UK. He was very helpfull sending me a new upper valve unit which he thought was faulty. But alas it was not. The unit kept on cutting out. I was not very happy. £3500 and it did not work.  Jim suggested I upgraded the unit to a Modular 30 unit this had two membranes instead of the one on the Smart 30 and he has never had an owner who has had a problem with this unit. I was sceptical but agreed.  The whole thing cost me £680 more but Jim did pay for the delivery of the unit.


Initially I thought that we did not need a watermaker and we managed without one for the first 5 years of our cruising life. However, we could only stay in an anchorage or bay for a limited number of days as we were governed by our internal water tanks which hold 350 litres each. They have lasted us 4 weeks but we had to be carefull of how much we used and eventually we had to leave to fill up with water.

Yes you can get water in the Med but in the western Med it always ment going into a marina.  This I thought was not going to be a problem. Well it turned out to be a financial problem. Marina costs were soaring.  In our pilot book prices were €12 to €14 a night, well it was more like €30 a night. Sometimes they would let you fill up water for around €7 per fill but not often.

So after our 2005 refit we decuded to invest in a watermakeer. Our friends Rowan and Roly have had a Seafresh Watermaker for many years but it needed a generator to run it so I went looking for a 12volt version. Not to many of these around. An Italien Company made the Schenker Smart 30. The sales info said it produced 30 litres of water an hour using 8 amps at 12volt. It sounded ideal. We bought one costing £3500. Now we can stay in a cala for as long as we liked water no longer a problem.  I fitted it in September 2006 ready for the trip back through the canals in November.

The weather was realy bad in late 2007 and we did not get away until 20th December, then only as far as Falmouth. Our initial idea was to get into the canals and winter somewhere near Paris but it was not possible so we cut our losses and wintered in Falmouth.

We had to leave the Marina on the 31th March as the price rose from £230 per month to £640 on the 1st April so we went up river and tied to a pontoon. Here we tested the Smart 30 but it peoduced very little water. I think the reason was the water temperature which was only 8 degrees celcius. The user manual stated the 30 litre production is at 25 digrees centigrade. Oh well never mind we wait until we arrive in the Med.