Bilge pump to 12V or to shore power?

[palinurus]

I have purchased a Hunter 27 recently and have some concerns with the bilge pump wiring. This was not factory installed but done by the previous owner, who may have been in over his head. I know I am/

The bilge pump runs off the 12V panel, and appears to run if on whether the bilge is wet or dry. But when I leave the boat docked with shore power, should it not run off that shore power instead? I was told to leave my battery off when I am plugged in and leaving the boat, but then the bilge wouldn't run in an emergency flooding situation?

is is wired wrong? Or should I just leave it running all the time?

[btrayfors]

Bilge pumps should be wired directly to the house battery bank, through appropriate switches and fuses. That way, the bilge pump can be powered even if the main 12V battery switch is off, and it's generally a good idea to turn it off before leaving the boat.

I don't know what you mean by "on all the time". Bilge pumps are generally installed with a float switch or other sensor switch which will activate the pump when the water rises to their level. Power to that switch should be left on all the time.

Be advised that bilge pump switches are notoriously failure-prone. The only really good ones cost more than the pump (like the UltraSwitch Junior or Senior). Best thing you can do with any other type switch is keep it as clean as possible and test it regularly.

Bill

[mitiempo]

Bill is right. The WaterWitch switch is good as well and not much more money than a Rule float switch.
Water Witch Bilge Switches
Water Witch Bilge Pump Switch

If your bilge pump is on all the time you either have a bad float switch or a manual position only switch for it.

[palinurus]

Thanks. I think you are correct (that the switch is broken). But I also am sure it's wired to a "bilge pump" switch on the 12V panel so it will go off if the main panel or battery is off.

I will investigate. Thanks for the tips.

[BarryL]

Hey,

You need to understand how your boat is set up. Once that is done you can determine if you want it that way, or if you want to change it.

Personally, I want my bilge pump to be powered two ways:

1. Directly from the house battery bank to the float switch on the bilge pump. This way, if the bilge fills with water, the float switch will turn on the pump and it will empty the bilge until the level drops low enough to turn off the float switch. The position of the battery switch (1, all, 2, off) doesn't matter.

2. Power from a switch on panel right to the bilge pump.This way I can turn the pump on manually and empty more water than the float switch would. This switch gets powered when the battery bank is on.

I've seen bilge pumps powered in all crazy ways. The way above is how I have mine set up and I like it like that.

Barry

[ahab211]

Between floats getting stuck and bad switches I just check mine regularly and pump it by hand pump. On my C&C 24 there is only a manual factory pump from the cockpit. Next year I may install an automatic pump I have at home. I got some good idea here and will probably wire it direct to the battery with a fuse. Where to run the hose out of the cabin is another question?

[SloopJonB]

You can't even trust factory setups for bilge pumps. My friends Hunter 38 came from the factory with the pump wired downstream from the battery cutoff. He had to completely rewire it so he could leave his batteries off when the boat was unattended.

[GaryHLucas]

What year is your Hunter 27? I had a 1976 and when I bought it, it had water in the bilge. The next year when the marina went to launch the boat they called me, because when they picked up the boat the keel wanted to stay on the cradle! You could see about an inch of light between the keel and the hull. I opened up the bilge and was shocked to see that the bottom of the boat around the keel bolts looked like loose fabric. I completely rebuilt the bottom, and installed a bilge pump too. The next season we had dust bunnies, and the new owner reported to me 8 years later that he still had dust. So I always wonder how many boats have keel problems, that everyone attributes to deck leaks and such. In the 1978 model Hunter changed from a keel recessed in a slot in the bottom to a short keel stub on the hull. This increased the depth of the internal stringers tremendously, and cured a big design flaw in the early 27s.

Gary H. Lucas