Problem with fresh water pump

[mlibkind]

This morning the fresh water pump for the main water system on my sailboat was working fine. We then motored 6 nm in 15 kts of wind and 2-foot seas. We ended the day at a marina. Later that day the water pump started cycling. It goes on for 2 seconds, goes off, and then repeats in 8 to 10 seconds.


The pump is a Jabsco 25 psi automatic water system pump (Model 31600-0292 ... has been superseded by a new version) and the system has an accumulator and particle filter. The water tank is 150 gallons and is nearly completely full.



Any ideas what is happening? Do I need to replace the pump?


Marcus

[rbk]

Loose connection somewhere causing leak and loss of pressure. Look for water weeping from a fitting.

[sailorboy1]

Theres either a leak in the system or the pump check valves are leaking back

[sparrowhawk1]

My guess is that there might be algae in the valves.

[mlibkind]

Thanks for all the quick replies and the suggestions.


I don't think it is caused by a water leak. At least there is no noticeable water reaching the bilge.



I do think the stuck check valves makes a lot of sense. I'm sitting out 20 to 30 kts of wind right now and will for the next two days. I have a spare pump (not an exact fit but usable) and will see if swapping it out helps. If so, it might be worth trying to fix the check valves because the pumps are very expensive.


Cheers.


Marcus

[Stewie12]

Clean the check valves

[AndyEss]

Until you try cleaning the pump valves, just
shut off the drinking water pressure circuit. When you need to use water, turn it back on. That will help you from draining your house batteries - and a lot of unnecessary pump cycling

[Cadence]

Originally Posted by mlibkind

Thanks for all the quick replies and the suggestions.


I don't think it is caused by a water leak. At least there is no noticeable water reaching the bilge.



I do think the stuck check valves makes a lot of sense. I'm sitting out 20 to 30 kts of wind right now and will for the next two days. I have a spare pump (not an exact fit but usable) and will see if swapping it out helps. If so, it might be worth trying to fix the check valves because the pumps are very expensive.


Cheers.


Marcus

This may sound stupid. try giving it a rap with something like a wrench.

[Stu Jackson]

Originally Posted by mlibkind

I don't think it is caused by a water leak. At least there is no noticeable water reaching the bilge. >>>>>>>>>>>>>>>>>>

It doesn't have to be a large leak. I had the same problem and traced it down to a small slit in the hose to the head sink which was way back under the engine. So little water came out and never made it to somewhere anyone could see.


A small leak MEANS you are losing pressure in the system, which is why the pump keeps cycling.


As always, whenever this recurring question appears, every single domestic water pump MANUAL has detailed TROUBLESHOOTING instructions.


RTFM, and good luck.

[Cheechako]

Either a minor leak, or air has become trapped in a hose somewhere. Culprits are often a bubble of air in hose loop/bend.
For leaks run your dry hand on every foot of hose. If wet your leak is near by.

[Mikado]

I had a similar problem and it turned out to be a loose connection on the water maker output to water tank hose. No water leak but the pressure would escape causing my freshwater pump to cycle.

BTW, a replacement pressure regulator for your pump is only a few dollars if that is what the problem turns out to be. I carry a couple spares.

[GordMay]

Originally Posted by Stu Jackson

... As always, whenever this recurring question appears, every single domestic water pump MANUAL has detailed TROUBLESHOOTING instructions...

Indeed ➥ https://www.pumpagents.com/pdf/Jabsc...31600-0292.pdf

[LittleWing77]

Geez, Stu - no need to be rude. He'd just rather have input from some humans. Which is why we're all members of this Forum.

Oh, and Merry Christmas!

Marcus, I've done the same thing as AndyEss and just switched off the circuit, only turning it on when I need water. As he says, this will avoid draining your batteries and burning out the pump until you can clean the check valves and/or find the leak (I'm voting for a hard-to-find leak).

Let us know, will you?

Happy Happy, Merry Merry,
Warmly,
LittleWing

[Mike Banks]

Probably not. I would clean all of the hoses, and also look for leaks. The tiniest leak can cause this. Also, if you are using an old pump with a pressure diaphragm operating a micro-switch, you will find an accumulator is a big advantage. If you are using an electronic sensor using a piezo system, I found they worked better withoiut an accumulator, but that is just me.

I also found, although this is not your problem, that the later pumps had rubbish el-cheapo bearings. They did not last long--and I replaced all mine with Japanese stainless steel pre-filled with lubricant sealed waterproof bearings--good for a few thousand hours of use.

Why they did not fit good bearings in the first place beats me--it would have added fifty bucks to the cost--and most of us would have paid it gladly to have a smooth and quiet pump. The difference was profound.

[chris mac]

We just had a similar problem. Pump would kick on for 2 seconds a couple times a night.(when no water was being used) turned out to be a very mild leak in the sink faucet. So no water into bilge, and not really any noticeable leak into the sink. It doesn't take a big leak to lose pressure and kick in the pump