Bilge Problem?

sqounk · Jun 24, 2012

When I approached my boat the other day I heard the unmistakable hum of a small motor. I hav since isolated the noise and it is the bilge pump.
For now I took the post offf the positve terminal and connected it only when I hit the water.

How do these work? I mean I have an inboard switch marked bilge that does cause it ton run when applied... Question is this: Does it power on (normally) even with the inboard switch off as a fail safe in case it needs pumping when you are not there? If so the fact that it is running with no water present means it is stuck in the up/on position? Or has a bad switch? I assume it is a float switch similar to a houses sump pump?

TwoFish · Jun 24, 2012

Re: Bilge Problem?

The pump should not be running all the time. The impellor wont be damaged by running dry but the motors are not designed to run continually.

What to do will depend on whether you have a straight bilge pump or a automatic pump and how it is wired.

If it is a straight pump just turn the switch off and only turn it on when you need to pump water out.

If it?s auto you could have a stuck float. Some models have a combined float switch and pump in one unit. Other units are separate. Take the pump out clean it and see what you find. They are not horrendously expensive to replace if you need to.

The other thing to look for is how the pump has been wired in the first place. Auto pumps can be wired in two ways.

1. Single circuit power all the time. This circuit can have a switch in it but it?s not necessary as the float acts as the switch. Should only turn on when water level in the bilge is high enough to trip the float switch.

2. Double circuit. As above but with an extra circuit that allows you to override the float switch. This allows you to turn the pump on manually. I have mine wired this way. It was easy to do as I have a separate pump and float switch. One circuit goes from the battery to the float switch then to the pump. The other from the battery to a switch on the dash to the pump. All circuits are fused. This way as soon as the main battery is connected the float switch is active and if water enters the boat the pump will work. The float switch is situated higher in the bilge than the pump so the pump can lower the water enough to allow the float switch to turn off. If I want to pump the last little bit of remaining water I can use the override switch.

You need to work out what type of pump you have and then how it is wired. If there are any identification marks on the pump you could try googling them. You could try turning the switch off then putting some water in the bilge to a level that submerges the pump and seeing if it switches on.

Good Luck