Proper location for bilge pump?-gctid816156

[Solandri]

I've suspected the bilge pump of being faulty, so I finally took the time to track it down. Good news is that it and the float switch function just fine. The bad news is their location. The pump is mounted underneath the front of the engine, and it's not even mounted in the center (lowest portion of the bilge). It's mounted about 3/4 of the way up towards the stringer supporting the engine. The float switch is even worse - it's also mounted under the front of the engine, but it's right up next to the stringer - the highest possible location.

Due to the location of the float switch, the bilge pump will not activate until the entire bilge area underneath the engine is flooded. Worse, if the boat sits with a stern-heavy attitude (which it usually does), water will spill out the limber holes to fill up the rear of the boat near the transom before the bilge pump ever activates.

Before I set about correcting this, I want to make sure there isn't some reason the pump and float switch are mounted where they are. I would think you'd want the pump to be as low in the bilge as possible, and close to the stern since the boat usually pitches up while accelerating causing water to pile up at the stern. And the float switch should be slightly above the pump. Is that right, or should I leave them where they are?

[Mr._Darcy]

I would leave that pump as is, and install another at the lowest point with it's own float switch. The instructions that come with the switch will tell you how to properly locate it with reference to the pump. You might even connect a dash light to tell you when that original pump comes on. It should only run if the lower pump fails or cannot keep up. The lamp will alert you that there is a problem. I have installed this set up in my boat as well as customer boats.

Greg

[2850Bounty]

A main engine bay bilge pump is there to take care of water in an emergency scenario.

It's float switch should be mounted at a higher elevation than the pump's lowest draw-down capability. In other words, the pump should be able to push enough water out so that the float switch can drop and open the circuit.

The float switch should also be powered by an Un-Interruptible power source.... such as the rear MBSS terminal #2.

It is common to see an independent additional and smaller bilge pump in this same area as well.