Experience rpt: 'Water Witch' bilge switch

[sildene]

I have Water Witch bilge switch that is normally in the yacht bilge where it encounters contaminated or salt water.

The past weekend we had torrential rain, and since I am in the process of repairing cockpit drains, I relocated the Water Witch to the cockpit to clear out rain water. It failed to switch.

I took it home for some simple tests.

For those unfamiliar with this switch – no moving parts; two exposed metal contacts; presumably it monitors the resistance between the contacts; when both are immersed in water the resistance changes and the switch triggers. It has anti-stutter circuitry. This is a nice and compact, fully sealed unit.

In my rudimentary testing, it would not switch reliably with fresh water, irrespective of battery level. It would switch reliably when a teaspoon of sugar or mud is added to the water.

It is not designed to switch when immersed in oil or fuel.

I have returned it to the retail supplier asking for an in-warranty response, which I have not yet received.

If anyone has had contrary experiences with this product please let me know – then I may consider giving it another go once I get a replacement. But I am now leaning towards scepticism.

Good info. I have been looking at these things for our boat. Which model did you try? I like the new model 101's as they can be fit into a really cramped space and can be attached using the hose clamp.

I can see how fresh water might not work as well as salt water given improved electrical conductivity of salt water.

When using these maybe wiring a mechanical backup switch would be a good idea?

[Strygaldwir]

The essence of the issue is that water (h20) does not conduct electricity. It is the impurities in the water that allow it to display conductive properties. Salt in the water makes the solution fairly conductive and a switch can measure this conductivity and turn on. If the water is particularly pure, like RO water or rain water, the switch probably will not work. Nothing wrong with the switch, per se.

Maybe you could suspend a salt lick in the bilge somewhere. When there is water present, it would dissolve a bit of the salt and trigger the switch.

Good luck,

[delmarrey]

Practial Sailor seems to favor the "Water Witch" pumps in "dirty water".
http://www.practical-sailor.com/issu...es/5224-1.html

[cal40john]

I have no experience with this product, but I was curious if they had a disclaimer that it doesn't work for boats in fresh water. It would be silly to market a bilge switch that doen't work in fresh water in my opinion.

From their FAQ page:

Does water need to cover both sensors to start pumping water?

Normally, no. It depends on if the water is grounded. Looking at the bilge switch with the wires coming out the top, the lowest sensor disk becomes the activation sensor so the water needs only to barely touch that sensor for 8 seconds to activate your pump. However, if your bilge water is not grounded or distilled water is used in the bilge, the water must also reach the upper sensor for 8 seconds to activate your pump



Customer FAQs

So it sounds like your switch is broken if their advertising is to be believed.

John

[sildene]

I used the model 217 (larger than the 101, and with non-stick coatings on the contact plates).

Originally Posted by learningcurve

Good info. I have been looking at these things for our boat. Which model did you try? I like the new model 101's as they can be fit into a really cramped space and can be attached using the hose clamp.

I can see how fresh water might not work as well as salt water given improved electrical conductivity of salt water.

When using these maybe wiring a mechanical backup switch would be a good idea?

[coachmiami]

The best switch in the world is Bob Merganthallers Ultimate PumpSwitch sold by West marine and privately branded.

I sold those to West marine 12 years ago. They have a lifetime warranty and are bulletproof.

Put them in and forget about it!

Not cheap though....

(but neither is raising up a boat!)

Miami
Trade a cat for a horse ranch?
www.higcountrystables.com