Engine Room Rehab

Posted: June 1, 2014

Make sure your electric bilge-pump system is ready to go.

By: Capt. Wilson Sheppard

Water can get inside a boat in a variety of ways: big waves, rain, leaky fittings/plumbing/tanks, washdowns and more. The most feared method of water intrusion, and rightfully so, is a hole in the hull.

No matter the method of water’s intrusion, electric bilge pumps are installed throughout a boat to draw in water that has come aboard and discharge it overboard. Surprisingly, they are not required by the Coast Guard on recreational boats.

My boat has a 2,000-gallon-per-hour (gph) pump with an external float switch in the engine room. Despite looking more like weird marine life than a dewatering device, the system is functional. I plan to install a new bilge pump, clean up the existing one and use it as a backup in the engine room.

Bilge pumps are usually neglected, because they are installed in the dark abyss at the bottom of the engine room, underneath v-berths and below cabin soles. But you need to pay attention to them, so we’ve got some ideas for identifying, troubleshooting and upgrading your bilge-pump system.

Unrealistic Expectations

Manufacturers calculate gph based on ideal conditions for maximum electrical power provided to the pump and a short unrestricted run of hose from the pump to the discharge. Therefore, a pump’s gph may be significantly less than what is stated on its packaging, so don’t skimp on the pumping power, because an inadequate bilge-pump system could allow water to rise, short circuit your electrical system, stall your engine(s) and ultimately sink your boat.

Station Identification

Locate the bilge pump(s) in your engine room and answer the following questions:

- What is the pump’s gph capacity?

- Is it designed for 12v or 24v systems?

- Is it activated by an electrical switch, an integrated float switch or water-sensing technology?

- What is the condition of the discharge hose? What is its diameter and length? What is the height of its run?

- What is the condition, size and length of the wiring?

- While you are at it, locate pumps installed in other compartments and answer these same questions.

Pump It Up

To have your bilge-pump system operable at its maximum output, you need to consider its capacity, plumbing and wiring.

In a single-pump installation, you should use the largest capacity pump that will fit in the lowest part of the bilge. For added dewatering capability, you might consider a dual-pump installation with a small-capacity pump low in the bilge and a larger backup pump installed higher. The second pump can be used if the primary pump fails or cannot keep up with the flow of water.

Next, make sure each pump in your system has a high-quality discharge hose, the inner wall of which should be smooth (not corrugated) to allow unrestricted flow of water. The length of the hose should be as short and straight as possible with a gradual incline to its overboard outlet. The hose should be installed out of the way, so it won’t be accidentally crushed or kinked.

For peak electrical performance, make sure your power sources (alternator, generator and shore power) are keeping your batteries fully charged. Wiring connections should be secure and waterproof. Any voltage drop will diminish a pump’s water output.

Finishing Touches

Each bilge pump should have a manual-override switch located somewhere it can be easily identified and activated during an emergency. The companionway, electrical panel or helm are typical installation locations.

You may also want to consider adding audible and light alarms to your system, which will ensure you are notified of water intrusion despite engine noise or being on night watch. Another option is a mechanical counter that will tell you how many times your pump cycles on and off, indicating the severity of a leak.

It’s probably not true that a scared crewmember with a five-gallon container is far more effective than any bilge pump, so be sure your system is ready for any water Mother Nature, a plumbing failure or excessive washing can send its way. Then you won’t have to resort to using salty language like, “Buck-et!”

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