I've been given a sailboat which is in a significant level of disrepair. Hooray, projects!

The problem I'm currently facing is that there's no water pressure, even when I turn on the switch that gives power to the water pump.

I took a multimeter to the wires that feed into my water pump, and I seem to be getting 12 volts there. That then leaves the problem somewhere past those wires. I'm pretty clueless on how to run it down, though.

Shurflo has a parts list (PDF) so if you know what's busted you can order individual pieces.

How can I diagnose this? I have lots of time but little in the way of financial resources. I also have little background knowledge but I'm keen to learn.

Book recommendations are more than welcome if you know any. I don't really know what this kind of repair is called, tho.

  • Some folks might consider this off topic, since it's not "Home" improvement. I'm on the fence since water pump repair can also be useful in a home, so answers might help homeowners as well.
    – Tester101
    Jan 30 '14 at 17:16
  • I have the same pump and same problem. On mine the pressure switch failed. I got a new pump. Nov 15 '16 at 23:57

There isn't much to go on but I'll give it a shot. You say you switch the pump on and don't get water pressure. Given that you're trying to diagnose using a multimeter, I will assume the motor does not run. Between the leads to the unit and the motor there is a pressure switch (#1 on the parts diagram). It could have failed.

More likely though is that the motor has failed. The motor will probably cost more than a replacement unit. (I was a yacht mechanic for 10 years and have tossed out more dead water pressure pumps than I can recall. No one makes a really good unit.)

If the motor runs when you switch it on then there isn't much you can diagnose with a multimeter. Open up the unit and look at the valve assembly. There is probably dirt holding open one or more of the valves or one or more are dried out and don't seat well enough to function properly. A rebuild kit (new valves) will fix it if the problem is from bad valves. Otherwise save yourself a lot of grief and replace it.

  • 1
    I want to add that there is a great book by Nigel Calder called: Boatowner's Mechanical & Electrical Manual. I recommend it to any DIY boat owner. Jan 30 '14 at 22:45
  • Mark, yeah you're right it just doesn't react when power is applied. So that sounds like a motor problem. I'm testing with a multimeter because that's the only tool I know how to use :) I'll grab the Calder book and see where I can get with that. Thank you.
    – canisrufus
    Jan 31 '14 at 16:16

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