I can't seem to get it right...please help

Hi,

Since we bought our new/used 1984 Ericson 30+ three years ago, the water pressure pump (a Shurflo pump) comes on every five minutes or so to restore pressure in the water system, even if there has been no water use during that time. We have resorted to turning it off unless we are preparing meals, after which it gets turned off again, but this isn't a satisfactory solution.

I have checked and re-checked the plumbing system, but without success. The boat has been well-maintained by previous owners and myself, and surveyed very well when I bought it--repairs done professionally, neatly, with good quality parts, etc.

The system consists of a main and a second plastic water tank, each with it's own deck fill and a ball valve enabling switching from one to the other, then the line goes to the pump, then through the galley and up the port side to the head which has a tap with attached shower valve. I have followed the lines through the boat wherever they are visible, snugged up any slightly loose hose clamps and connections, and they all have teflon tape visible at the connections. There is no sign of any leaks. I have reviewed the Ericson plumbing plan for this model boat, and mine conforms to that, so there is no indication of any modifications that could have caused this problem.

A friend suggested I remove the hose from the "out" end of the water pump, add a dummy hose with a plug in the end to see if it still cycles on/off. I did that and was amazed at the pressure on the plug--it blew the wooden plug right out of the hose, so I re-inserted it, taped it with rubber self-amalgamating tape and my hand over it, and it held. But the pump "chirped" every 5 seconds or so, even though there was no leaking at the plug--somehow it didn't like this set-up, so it didn't help me figure out anything more about whether there is a leak after the "out" side of the pump.

So I have no idea what I can do next to solve this, and would appreciate any advice. I don't know if the pump itself could have a pressure leak problem. There is no leakage at the pump and it looks entirely dry.

Thanks for any useful advice.

Frank

I have checked

Your experiment ruled out a downstream leak as the cause. So if water isn't leaking out of the pump itself, I would suspect that the internal seal is leaking "upstream" and allowing the pressure to drop, causing it to cycle frequently.

If so, I would guess that rebuilding the pump with a commercially available rebuild kit from the manufacturer is worth a try. I used to keep one aboard for breakdowns, and think I got the part number from their web site, and ordered it from West Marine.

Thanks, Steve. Are they hard to rebuild? I'm not very mechanically inclined, though willing to give a rebuild a try if it's not too tough.
Frank

Not hard at all. It just involves removing the screws that hold the body together, prying it apart, and reassembling all the rubber bits and springs and O-rings in the proper order. This is a case where taking a series of photos with a digital camera on hand to document what it looks like as you remove parts can be worthwhile. A full repair kit will also have a spare pressure switch, which is usually the first thing to go on a water pump.

Steve, thanks for your quick reply. I'll give it a try and hope that solves the problem.
Frank