Fresh water pump cycling

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John T1594

John T1594

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Jun 4, 2004
834
Hunter 340 Forked River, NJ
Driving me crazy!!! I have checked and tightened all of the grey Qest fittings on the fresh water lines in my 2000 H340 and the fresh water pump still cycles about every 3-4 minutes - just enough to keep us awake at night. I looked under the sinks, at the stern shower, the hot water heater and the "T" fittings but I can't find any leaks. Is there a problem with the pressure regulator on the pump?
 
T

Tony

Same problem

Had the same problem. Was told to bleed air did that no help i was finally just turning it on at the breaker when i needed it and otherwise sutting off power to not be driven nuts Next was told to rebuild and get a kit turns out the pump kit for the one in my 340 no longer made Company actually sent me a new pump!! Put it in and solved the problem. Get on their website
 
Peggie Hall HeadMistress

Peggie Hall HeadMistress

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Dec 2, 1997
8,915
- - LIttle Rock
Prob'ly just needs a new diaphragm.

A failing diaphragm creates an "air leak" that allows the pressure to drop, which causes the pump to cycle to restore it. At first, it may only cycle for a second or less every few hours...but as the little hole in diaphragm gets bigger, the pump will cycle more often and longer each time...till eventually it runs continuously without pumping any water. You should be able to order just a diaphram kit for it...cost is under $20. Be sure to have the make/model/AGE (or serial #) of the pump handy, 'cuz diaphragms even for the same make are not "one size fits all."
 
B

Bill O'Donovan

I'm with Scott

Simple solutions are often the best, or at least the least-expensive.
 
K

Karl

Pump at night

Never leave the pump on when your not using the water. You could pump your tank dry and not even know it.
 
Peggie Hall HeadMistress

Peggie Hall HeadMistress

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Dec 2, 1997
8,915
- - LIttle Rock
Turning the pump on and off is MUCH harder on it..

'Cuz every time you turn it off, the plumbing loses pressure...the pump has to run just to reprime it. If you maintain the system and pay ANY attention to the difference between "normal" sounds on your boat vs. something running that shouldn't be, you won't drain the tank without knowing it. So turn the pump on when you come aboard...turn it off when you leave. And learn to listen for it.
 
S

Steve Dion

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Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Save some money.

John: You may save yourself some money by shipping the pump back to the mfg for repair. They check them out on the bench and will tell you if it is worth putting a kit in it. I had a pump that did the same thing. I sent it to the mfg and they told me to junk it. I asked them to do it for me. I already had a backup pump installed. I have done this a couple of times over the years and have had great success with their repair departments. They usually charge around $25-30. I currently have one of the Flotjet VSD pumps. It is very quiet and only took about 20 mins. to install. It has completely eliminated any cycling too. You can purchase these pumps from Camping World for about $160.
 
J

JC on Bainbridge

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Jul 17, 2005
586
Hunter 37.5 Bainbridge Island - West of Seattle
Extend the pump's life, add a accumulator tank

One reason that causes the pump's diaphragm to fail is the frequent on/off/on/off during use. The start and stop cycle puts a lot of wear on the pump. It is also very noisy and annoying. I would suggest that you install a accumulator tank. It goes after the pump. This will reduce the need for the pump to cycle on/off, reduce wear, and sometimes you can use the faucet for a quick rinse, and the pump won't come on at all. Of course, you still need to fix the pump 1st.
 
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Steve Dion

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Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Not needed on a VSD pump

JC: Flotjet actually recommends NOT using an accumulator tank on the VSD pumps. I have no idea why. I had one on the original system, so I just left it in place.
 
John T1594

John T1594

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Jun 4, 2004
834
Hunter 340 Forked River, NJ
Thanks for the info

Thanks to everyone of the information, opinions and advice. I'll look into fixing the pump over the winter layup. BTW - I turn off the breaker when away from the boat and at night. The Admiral, however, has a lot to say about having no water pressure when she needs it.
 
Rick D

Rick D

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Jun 14, 2008
7,182
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Steve is Correct (Of Course...)

They don't recommend a high-bypass pump be used with an accumulator tank. I put in a standard pump after I put in a tank in my last boat. Rick D. PS: my pump was beginning to cycle often. I found that the hot water heater was broken and it was weeping water, but it drained into the bilge so it wasn't noticable until it got bad. Rick D.
 
Fred Ficarra

Fred Ficarra

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Dec 2, 2003
4,245
- - Seabeck WA
One more idea

My camper has one of these 'marine pumps'. At re-commissioning last year the pump was doing the repetitive cycle routine. I took it out and disassembled it. (Sorry, I took it apart.) Nothing! It looked perfect. I put it back together. Same thing. On/off. After repeating the search for a malfunction at least three more times, I noted that the diaphragm had a slimy feel to it. I washed it in soapy water and scrubbed the slime off with a fingernail brush. Problem solved. A year later it still works perfectly. Hope that's all you find.
 
B

Brian

And another idea

We too were baffled for a day or two at our pump's occasional on/off. Turned out the hose inlet on the stern was not closed tightly and although technically it's an "inlet", water was able to go out that way too when the system was pressurized. The water was trickling in a tiny stream down the outside stern of the boat where we didn't see it. Check the hose inlet if you have one.
 
P

patrick

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Jun 7, 2004
944
Birch Bay Washington
Mine did this too

It turned out to be salt particles in the outlet of the aluminum tank caused by bleach. It had plugged the line almost completely. The pump would suck air into the feed line. My suggestion is try using a different water source and see what it does before you spend a lot of time and money replacing parts.
 
jk kudera

jk kudera

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Dec 2, 2003
209
Hunter 34 Forked River, NJ
Did you check

if the hot water heater is leaking? That was my problem. It leaked, water went into the bilge, and out of sight!
 
A

AndyK

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Mar 10, 2004
195
Hunter 33 Salem, MA
My water pump too...

After disassembling my water pump and putting it back together I found the wash down spray hose on the rear of the boat was leaking because somebody had left the valve on. The water was going to the bilge so I could not trace it. Turned it off and no more cycling.
 
V

Vernon

Particles in filter/screen

I had the same problem develop earlier this year on my 376. After repeatedly checking every connection on the boat, I noticed white particles in the clear plastic "in-line filter" that is installed just upstream of the pump. It was a simple operation to clean them out and the problem went away. I just can't explain why.
 
P

patrick

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Jun 7, 2004
944
Birch Bay Washington
Vernon, those particles

are an insoluble aluminum salt caused by chlorine bleach reacting with (eating up) your water tank. Mine was so full of these that after one particularly bouncy sail, they almost completely plugged the outlet fitting on the tank. The walls of the tank were coated with this stuff. It looked like barnacles. The pump would suck air into the line and pressurize the water lines with a lot of air. The air would leak out or be absorbed into the water in the pressure side. Then the pressure would drop and the cycle would start all over again.
 
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