Schenker Zen 30 watermakee

[FBD]

Hello
I bought the above watermaker and had it professionally installed about four months ago. For the first two months it performed as designed, making about 8 gph of water at ten amps. It created 7.5-8 bars of pressure. Then it started making on 3.5 gph at 5-5.5 bars of pressure. I have done all Schenker said to do: through hull is open and working, strainer is clear, I replaced the micron filter, pursed air from the system several times and even replaced the pump motor. The motor is getting 13.24 volts. Nothing has worked. Does anyone know what might be causing this problem and how I can correct it?
Thank you for your time.
Franklin

 

[garymalmgren]

4 months old.
Isn't there a warranty?

gary

 

[FBD]

4 months old.
Isn't there a warranty?

gary

Yes, but they are far away and slow in any real help. There is no one local who works for this company.

 

[dlochner]

How are the membranes. If they have become clogged, the output would be reduced.

 

[FBD]

How are the membranes. If they have become clogged, the output would be reduced.

That is a good question. They said the membrane could last up to seven years. It has about 100 hours of use. I have used the system in inlets on incoming tides and in the ocean. It is making very good water (35 parts per million), but just not making very much.

 

[dlochner]

That is a good question. They said the membrane could last up to seven years. It has about 100 hours of use. I have used the system in inlets on incoming tides and in the ocean. It is making very good water (35 parts per million), but just not making very much.

The operative word is "could."

 

[FBD]

The operative word is "could."

Oh my gosh that is awesome. Maybe it is the membrane but what limited info I have read said that as the membrane gets dirtier, the quality of water goes down. I really don’t know.

 

[JamesG161]

These membranes can , like in the movie Ghostbusters, get "Slimed".

You might look up "Regular Maintenance" in your Owners manual.

Jim...

 

[FBD]

These membranes can , like in the movie Ghostbusters, get "Slimed".

You might look up "Regular Maintenance" in your Owners manual.

Jim...

I did and do. I live on the boat and back flush the system once a week. It could be the membrane but Schenker never said that. They asked that we measure the output of both the good water and brine. But I am open to all possibilities.

 

[JamesG161]

From you owners manual...
Maintenance is very easy. Watermakers like to be used regularly. If left standing for 10 to 15 days they will need flushing through. This operation can be performed automatically with electronic control or manually. During long standstills it will be necessary to flush the watermaker with biocide to avoid growth forming in the membrane.

Jim...

PS: Use for drinking and cooking only. Bathing uses too much potable water.

 

[Ralph Johnstone]

It is making very good water (35 parts per million), but just not making very much.

With that statement, I would suggest going back to your initial remarks :

For the first two months it performed as designed, making about 8 gph of water at ten amps. It created 7.5-8 bars of pressure. Then it started making on 3.5 gph at 5-5.5 bars of pressure.

Congrats on good record keeping on your part. There are one of two (and hopefully its only one ) causes for the drop in the pressure and discharge you listed above :

a) There is lack of supply from the pump, and the causes here are many as you may have guessed eg. motor output, check valve leakage, plugged strainers, etc, etc.

OR

b) There is increased demand in the membrane housing area and again these causes may be due to more that one item eg. membrane leakage, one or more leaking "O" ring seals, etc, etc.

Dealing with the present, what is the current amperage draw of the pump ? We can rule out motor drive problems as you recently replaced the motor. Does your owner's manual deal with pump disassembly and repair ? If so, another consideration is the condition of the check valves in the pump. Can you remove them and check their condition ? Keep everything super clean while the pump is open. Check for "O" ring conditions. Do they look healthy ? Can you check the condition of the inlet hoses to ensure they are clean ? You seem to have already dealt with all of the other causes of reduced pump supply. The above work requires a good supply of tools and mechanical dexterity so don't start this unless you are well prepared.

The leakage in the membrane area is more difficult to determine but can you compare the original output of treated water + concentrate discharge as compared to the current combined output of these two items. I don't think you have these numbers but anything may yield a clue.

Please reply with any further numbers you may have and we'll see where we go from there.

 

[SycloneDriver]

I suggest that you figure why the operating pressure is low. The pressure is critical to push the water through the membrane. Fix the low pressure and your output volume will go up.