Watermaker Virgin

[TQA]

I bought my boat a year ago and it came with a Spectra Ventura 150 deluxe watermaker fitted.

Now I have never had a watermaker before so it was with some trepidation that I fired it up for the first time yesterday but I followed the instructions, ran it unpressurised to flush out the 'pickling' chemicals then closed the pressure relief valve and was gratified to see the product flow start after a few minutes and the water to taste sweet. The pressure was a little lower than the handbook suggested at about 65 psi but we are in warm Caribbean water so I was not concerned.

However after about a hour it has stopped making water and the pressure is now fluctuating between about 15 psi and 45 psi with a more pronounced pulse in the brine output.

The intake filter is clear.

What has gone wrong?

[mitchbrown]

TQ

There should be a Raw water strainer connected to the thru hull fitting and then a low pressure pump and then probably 2 filters which probably are 10 micron. if the pressure on the low side is to low it would have to be one of these 3 components causing the problem. there may also be an oil seperator filter in the mix and one of the filters may have a charcoal element in it. If the pressure gets to low the machine will usually shut itself off.

Mitch

[Tel321]

A Spectra Deluxe 150 has no electronic controls. There are only two possible problems that would cause your watermaker to fail as you described. The most likely cause is that the feed pump head has failed. Not unusual for one that has sat for too long. The simple test for this is to run the watermaker with the pressure relief valved closed. While it is running pinch off the brine discharge hose. At the same time watch your pressure guage. On a good feed pump the pressures should quickly rise to around 125psi and the pump motor should shut off for a second then it will consistantly shut on and off. If this happens your feed pump is good. If the pressure will not rise to this limit and the feed pump continually runs with the brine discharge pinched off the feed pump has to be replaced. Though these pump heads are propriatary to Spectra it's an easy fix you can do yourself. If with the brine discharge pinched off the feed pump rises to 125psi but when you release the brine discharge the gauge falls back to reading 15-45 psi then the Clark pump needs to be re-built. Send it back to Spectra and they will refurbish the Clark pump and send it back. If it is the Clark pump don't hesitate to PM me for specific removal procedures of the Clark pump before proceeding.
Also the Clark pump has two strokes. The pressure guage when it goes up to 45psi and falls to 15psi is only one stroke showing what's going on on one side of the Clark pump. The very next rise to 45psi and fall to 14psi is the other side of the Clark pump. Both strokes should read the same 45psi-14psi.
Good Luck,Tellie.

[TQA]

Tellie

Thanks for the comprehensive reply.

My feed pump looks like it is OK as I get the 125 psi with the brine pipe pinched off so it is the Clark pump then.

As I am out in the Windward Leward island chain I have downloaded the field repair guide for the Clark pump and will give it a go myself.