Emergency Bilge Pump

[Bill D]

I finally got my emergency bilge pump install finished today. I call it an emergency pump because it will run on a float switch that is installed about 8" above the bottom of the engine compartment. I want it to function only after the primary pump cannot keep up. I also installed a light and buzzer at the helm to let me know that the backup is running. There is a bill of materials at the bottom of the thread.

Here you can see the bilge pump and the Water Witch 101 float and the 2,000 GPH pump. The angle of the photo makes it a little difficult to see, but the switch sits near the top of the engine mount support structure.


The pump requires a 1 1/8" outlet hose. I ran a new dedicated hose to its own outlet. I ran into a little bit of a situation when I tried to run the outlet. On the LS boats, the shower tank sits right in front of the original bilge outlet and shower vent. The problem with the shower tank is that you only have about 2-3" of clearance between the tank and the hull. So, the through-hull fitting would not have room for the hose to attach. There is a nice part... the shower vent is only a push-through type and requires less depth. So, I chose to relocated the vent. I moved too fast to take a complete before photo, but you can see where the vent originally was, where the second outlet went, and the relocated vent.





I wired the pump and alarm circuit to the Aux panel I located in the battery compartment. The panel is wired to the house battery switch. If the switch is on, the panel is live. I used a relay (that's the black box with the blue and yellow wires coming out of it) to activate the alarm. For the alarm I used a simple buzzer/light combo.

Here is the panel and relay.

And the alarm. It is located under the helm. I also utilized a spare switch for a "silence" function. I figured if the worst case scenario happened; the boat is taking on water, both bilge pumps are running, and we have to figure out what to do... the last thing we want is a buzzer chirping at us.


2,000 GPH Bilge Pump - https://www.amazon.com/gp/product/B...CM/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Water Witch Bilge Pump Switch -https://www.amazon.com/gp/product/B00CMWLHX8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Bilge Pump Plumbing Kit -https://www.amazon.com/gp/product/B004XACR9...90/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Black Thru-Hull Fitting - https://www.amazon.com/gp/product/B000N9NWZ8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
14AWG Wire (for pump power) - https://www.amazon.com/gp/product/B00MI59JD4/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
18AWG Wire (for alarm and aux circuits) - https://www.amazon.com/gp/product/B0154MAECC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Alarm Buzzer - https://www.amazon.com/gp/product/B00Q1B2730/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[buckbuck]

Looks good @Bill D
That is a nice write up so the next guy can gather information. You planning on doing sub moves?

 

[swatski]

@Bill D Nice write up! I like a dedicated outlet. But wonder the reason to have the emergency pump not wired directly to the battery. My set up would be direct to battery (w/a fuse), I figure if the boat is taking that much water I don't want to worry about anything else. Also, the switch is for salt water use only, or am I reading it wrong.

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[AZDANSX230HO]

Nicely Done!!!

 

[Bill D]

@swatski Its basically direct to the battery. It goes battery -> house on/off switch -> distribution panel -> float switch -> pump. The reason I went through the house switch is so I can turn it off. The switch itself uses electricity (0.004 Amps) so I want to be able to shut everything off when it's on the trailer.

The Water Witch can be activated by anything except fuel and oil. I'm not sure how little oil it takes to make the switch not activate. That will be something I'll have to check out.

 

[Bill D]

@buckbuck a sub move seems like a logical way to test the pumps.

 

[buckbuck]

 

[tdonoughue]

Very nice install! And shockingly similar to mine (but I didn't do the switch and alarm--nice touches there). Very good job and nice write up!

 

[Bill D]

I was able to finish up the install and test the new bilge pump this weekend. I got my wife to take a short video of both the stock pump and the second pump running. Significantly more water ejected with the new pump compared to the stock 750gph.

A couple thoughts from the test run:

• The stock pump can almost keep up with a running garden hose. (Makes sense, 3/4" garden hose and 3/4" pump outlet.)
• The float switch placement for the backup pump is too high. I'll need to lower it about 2" to get the performance I desire.
• The switch says there is a 16 second off-delay, but I'll have to look closer to see if that is actually the case. It seemed that the pump cut off as soon as the water level got below the switch, which happened very quickly even though the garden hose was still trying to fill. I would rather have a high-level on, low-level off setup, so I may be working on that.
• The alarm worked exactly as desired. The little light/buzzer is very loud and will easily get my attention when alarming. Along those lines, I'm really glad I put a switch in to be able to disable the alarm. It would really add tension to an already bad situation if the buzzer kept going off while trying to troubleshoot a leak.

Here is a short video of the pumps. The first outlet is the 2,000gph pump, and the second is the 750gph. I plan to perform another test and get better video. I'll update this thread as soon as I do.
https://www.dropbox.com/s/l2t9t348y7hdxje/File Apr 03, 8 44 05 AM.mov?dl=0

 

[jameskeller76]

Did your gelcoat crack when drilling?

 

[jcyamaharider]

Did your gelcoat crack when drilling?

View attachment 53549

That's the factory port

 

[Bill D]

@jcyamaharider is correct. That is the factory 3/4" port. The boat came with a gouge in the rub rail just above and aft of that port. I think the previous owner had a run in with a dock and that's what caused those cracks.

 

[2nazt]

While repositioning switch, also remember the boat may be at an angle while in use causing more water to be farther back also, so take note to make sure nothing further back is submerged that shouldn't be.

 

[robert cabrerea]

One of those add ons you hope you never need. But glad if you did it. Especially if you have pto shaft failure. Great job and write up.

 

[Julian]

If you plan to do this and want the alarm, I'd just go with the Rule Bilge alarm to make it a bit easier. It can be used to trigger the bilge as well as the alarm. The alarm does not have a built in silence function though (but you could run it through a switch)

 

[Bill D]

The rule bilge alarm is great for someone looking for an out of the box solution.

My little buzzer only cost $6 though.

 

[jdonalds]

Bill D. Nice plan and execution. I too installed a Water Witch several years ago. I don't trust float switches. the Water Witch is very easy to test using a wet rag. It has worked perfectly all these years.

 

[scokill]

Here is my emergency bilge pump.... https://www.wakemakers.com/straight-line-super-sumo-pump.html doubles as ballast pump.

 

[Bill D]

So while doing my pre-Bimini bilge pump PM and test, I did a super scientific experiment to see what the true(ish) capacity of my bilge pumps is. With the garden hose filling the bilge, I took a 5 gallon bucket and held it under the pump outlet to see how fast it could pump out 5 gallons. The results are below. Both pumps operated at around 85% rated capacity.

 

[swatski]

So while doing my pre-Bimini bilge pump PM and test, I did a super scientific experiment to see what the true(ish) capacity of my bilge pumps is. With the garden hose filling the bilge, I took a 5 gallon bucket and held it under the pump outlet to see how fast it could pump out 5 gallons. The results are below. Both pumps operated at around 85% rated capacity.

View attachment 58685

That also indicates that your plumbing is done and sized correctly and does not limit the pumps' output. Well done sir!

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