Schenker watermaker

[Witte Raaf]

My Schenker wm gives me lots of problems. the water is salty (950 ppm) and undrinkeble.
According to the dealer are there hadrly any problems with this wm. I do not believe this and want to do some investigation.
my pump press. = 5,8 and ppm 950.

Please report to me your experience.

Thank you
Jan

 

[rivonia]

Shenker water makers

we have the same water maker as you and have no problems at all. I can only think that you are not back washing with pure water or you have not changed the filters as often as you should. Have you been in touch with the supplier?

 

[Manuel]

My Schenker wm gives me lots of problems. the water is salty (950 ppm) and undrinkeble.
According to the dealer are there hadrly any problems with this wm. I do not believe this and want to do some investigation.
my pump press. = 5,8 and ppm 950.

Please report to me your experience.

Thank you
Jan

Hi, your second post on the same subject and my second reply Have you actually tasted the water (product) or are you relying on a TDS meter? I just want to establish what the problem is in the first instance. Watermakers are very simple bits of kit in the 'science' sense and salty water would tend to suggest bad seals in the membrane holder. That is not very common.

Does the water actually taste salty or are your concerns due to a reading from an instrument?

If it tastes good it is good, and fix the instrument. If it tastes salty tell us a bit more about the installation. When, by whom, in what, when last working normally? With no clues nobody can diagnose the problem for you but there will be hundreds of watermaker users here many have designed and built their own and there is a lot of specialist knowledge.

Schenker is a good maker so you haven't bought a sow's ear and you can relax.

 

[ccscott49]

Aquafresh

I have an Aquafresh watermaker and I am about to change the membranes on mine, as the water is salty, (taste) the seals are OK, so the only way salt water can get into the fresh side is through the membranes. Mine are 210+VAT and I need three, so not a cheap repair! Pity. This is the first time I've used it in anger so to speak. Not my fault, bought the unit secondhand and its just not been maintained properly, so now I'm suffering for my cheap purchase, maybe I should have sent it to Aquafresh, before fitting to have it checked out and tested, 20-20 hindsight.

 

[Manuel]

I have an Aquafresh watermaker and I am about to change the membranes on mine, as the water is salty, (taste) the seals are OK, so the only way salt water can get into the fresh side is through the membranes. Mine are 210+VAT and I need three, so not a cheap repair! Pity. This is the first time I've used it in anger so to speak. Not my fault, bought the unit secondhand and its just not been maintained properly, so now I'm suffering for my cheap purchase, maybe I should have sent it to Aquafresh, before fitting to have it checked out and tested, 20-20 hindsight.

Dried out or chlorine attack? Both are lethal.

 

[ccscott49]

probably dried out, dunno what to look for, just going to replace them.

 

[Manuel]

probably dried out, dunno what to look for, just going to replace them.

Don't wear the sackcloth for too long. Just bad luck. Keep them wet clean and free from chlorine. Use them lots. Never use non recommended chemicals of any kind, only the manufacturers own recommended.

 

[Witte Raaf]

water tast

Hi folks,
my water tasts realy salty. I checked my ppm meter on mineral water and than it reads 180 ppm so the meter must be ok.

What is your pump presure? I think mine is too low (5.8)

 

[Manuel]

Hi folks,
my water tasts realy salty. I checked my ppm meter on mineral water and than it reads 180 ppm so the meter must be ok.

What is your pump presure? I think mine is too low (5.8)

OK I wanted to establish that we really had a problem. TDS meters are very unreliable. The tongue is a much better instrument for the future.

No, sounds about right. The pressure needed to force seawater through the membrane depends on the salinity and the temperature of the water. It is about 56 Bar. The Schenker has a pressure amplifier (as does the Spectra) which multiplies the pressure by a factor of 10. It's a bit like the master and slave cylinders in a car braking system. As soon as the pressure reaches that needed for water to flow through the membrane it is limited to that level. Working backwards, if you have typical seawater that needs 56 Bar then the Schenker would be running at 5.6 Bar. These instruments are not accurate, sea water and membranes vary so 5.8 sounds like a good reading.

Either the seals inside the high pressure containers are leaking or the membrane is ruined. This can happen due to chlorine or being allowed to dry out.

If this is a new machine won't the dealer sort it out for you? Most watermaker manufacturers protect their reputation by giving excellent service and Schenker has a good reputation.

 

[jeremyshaw]

To add to Manuel's advice, faulty seals usually lead to excess production because the salt water is bypassing the membrane. If your flow rate is higher than usual then the seals are the most likely cause.

In my experience membranes don't suddenly produce salty water, failure (pace grave abuse) is a more gradual thing - although your identification of salty water may hit a tipping point. Bypass of some kind (incorrectly fitted seals, cracked fittings) is more likely.

A possible installation error is to allow the water to syphon out of installation when not in use, thus drying out the membrane(s). So if your installation is new maybe consider that aspect.

Another common installation error is the use of brass nipples. Where these are set into the plastic of membrane caps they can expand differentially and crack the membrane - the water runs quite warm after a while. It happened to me...

 

[Spicemariner]

We have had the same problem with our Schenker since we bought it in 2002. We have tried everything, new membranes, pumps, seals. Nothing makes it produce water at less than 650ppm. If we try to use it on one pump, then the quality can drop over 1000ppm. Same meter used on other folk's water shows 180 to 300ppm, so it is not the meter. Schenker were not really very helpful and suggested that 850ppm was really OK. We intend to replace our membranes once again once we reach the Caribbean this autumn (we haven't used the watermaker since arriving in States last year). We think we have a lemon!

 

[Manuel]

We have had the same problem with our Schenker since we bought it in 2002. We have tried everything, new membranes, pumps, seals. Nothing makes it produce water at less than 650ppm. If we try to use it on one pump, then the quality can drop over 1000ppm. Same meter used on other folk's water shows 180 to 300ppm, so it is not the meter. Schenker were not really very helpful and suggested that 850ppm was really OK. We intend to replace our membranes once again once we reach the Caribbean this autumn (we haven't used the watermaker since arriving in States last year). We think we have a lemon!

I am very surprised. We prefer our watermaker (Spectra) water to any city water, it is as sweet as honey. We are sad when cruising comes to an end for the winter to go back to city water. The technology is the same and the membrane maker is almost certainly the same, there are only two makers in the world, I think. If the pressure is getting to the membrane it must be a flow past the seals, I think, unless the membrane is dead. Is there a Schenker owners' group, try googling?

I will be interested to hear the outcome.