Fresh water pump cycles often

[Montenido]

Hi folks,
We just returned from 15 days of cruising in the Sea of Cortez, which was amazing. However, I noticed the our pressure water system has begun to cycle every 15 minutes or so. I can't find any obvious leaks and was looking for some suggestions for trouble shooting the problem. I do have an accumulator tank in the system. Any and all suggestions would be much appreciated.

Cheers, Bill

 

[Pau Hana]

What pump do you have?
Any excess water in the bilge? (Loose connections/cracked lines)
Can you bypass the accumulator?

It’s simply a process of finding where the pressure is bleeding off.

 

[Ski in NC]

I had that happen on my boat. I think my pump is a Flojet. Found no leaks in the boat plumbing. Pump was leaking back internally.

For giggles, I opened a few spigots and just let the pump run free flow for like ten gallons. Theory was there was some crud in the pump check valves.

It worked!! Put system back to normal, and for the last few years pump holds pressure just fine.

That was a cheap fix!!

 

[HopCar]

I think Ski is right. If the you can’t find external leaks, the water is leaking back through the pump. It’s a very common problem.

I’ve never heard of Ski’s fix before but it’s certainly worth a try. If that doesn’t work just stick new valves in the pump.

 

[AlaskaProf]

I had this happen last summer. In my case it was a loose clamp, but the big clue was that one of my bilge pumps was cycling periodically. If that isn't your case, it is almost certainly a failed check-valve. Some are external.

 

[healhustler]

Dang, Ski. What a great tip!

One other thing though, I also had the same problem and couldn’t find the leak. Strangely though, I did find the humidity in the machinery space a bit more than usual. Checked again and again. Finally, when doing some other wiring below, I felt something on my cheek. It was a line leak so fine that I couldn’t see it, but I could feel it on my cheek. Checking by hand, nope...couldn’t feel it there either. Replaced line, viola!

 

[Montenido]

Thank you all for the prompt suggestions. I found the leak, it was a compression fitting at the house filter. That grey polybutylene stuff. I removed it and applied new Teflon tape to the threads and tightened it until the leak stopped. I hope those plastic couplings are strong because I had to cinch it down pretty tight.

Thanks again for the responses.

Cheers, Bill

 

[DrissZougari]

The pump is cycling because there is a leak in the system. if it is not the pump it self loosing pressure internally , then look for the obvious locations such as, dock side hook up if you have (pressure regulator), anchor washdown, cockpit washdown, ice maker if you have one...….etc.
good luck,

 

[fletch]

If the pump has a bladder, i.e. I have a Jabsco 31620, a defective bladder would cause excessive cycling with no leak, as the system would control on low pressure with no surge volume, worth looking at if you have a similar system.