By Active Captain
Bilge pumps and anchoring have a lot in common. They seem so simple. And yet, there are small details that can make big differences. And like anchoring, bilge pumps are one of the key safety elements on every boat.
Throughout this summer, Red Head has been swarmed with mechanics and techs from Zimmerman’s who are rebuilding some of the systems. This has put us in daily contact with exceptional boat builders and mechanical experts. Nearly every day there are over 100 years of experience replacing and fixing things on the boat. Conversations often develop as we’re down in the engine rooms doing projects ourselves. These conversations created many, “I never thought about that” reactions by us.
Here’s just one of them.
You likely have multiple bilge pumps in your boat. If you’ve been boating for any length of time, there are often a few that burn out or go bad. This can sometimes happen because of bad float switches and automatic mechanisms that turn the pump on and off – the potential subject of other newsletters. But there is something so basic that we had never realized about bilge pumps.
Red Head has about a dozen bilge pumps of various size – 800 gallons per hour (GPH) to 2000 GPH along with a huge, central emergency bilge pump and fire system. Some bilge areas are larger and have larger pumps while sump pumps and condensation collection basins have smaller pumps. That makes perfect sense. Or does it?
There are 4 larger pumps in the main bilge of the boat – they are 1500 and 2000 GPH pumps. But they keep failing. Two failed in June and were replaced. Another failed this month.
“The problem is the outflow hose,” said Caleb as I was expressing frustration about the poor quality of the pumps and how they should be lasting much longer. “The hose?” Come on – what could be simpler? Then he showed me.
For whatever reason, every thru hull outlet on the boat has a 3/4″ opening. Caleb showed me that the 2000 GPH pump that failed has a 1-1/8″ port on the pump. It’s designed to push water out that size hose. To connect to the 3/4″ hose, an adapter was placed at the pump. That restriction of water creates resistance to the flow. The pump has to work much harder to overcome that immediate restriction. It ends up burning out faster.
Now, look at an 800 GPH pump. It comes with a 3/4″ hose port. The pump manufacturer is telling us to use that pump for a 3/4″ outlet. But we’re not listening.
So as a first step in making your own bilge pumps more reliable, go check them and the thru hulls. Are they matched in size? Are you experiencing shorter life on the larger pumps? Perhaps the next switch should be to a smaller pump that will push just as much water, but not burn out. They’re also much less expensive.
There are many other things we never realized – hose configuration, lift, fittings inserted, and especially check valves. If there’s interest in more info about bilge pumps, let us know and we’ll add more to this secret life series over the next few months.