Fresh water pressure issues

K

kgodfrey

.
Dec 12, 2012
5
Catalina 400 Atlantic Highlands
Ron,
Since you fill you tank until water comes out of the vent and the system works well until a certain amount of water is drawn from the tank, it seems to me you are creating a vacuum inside the tank. Is your vent line run in such a way that a water lock is created? Do what a previous poster mentioned, remove the water fill cap and see if the problem goes away. If yes, then the vent is the issue.
Another simple test is run a length of hose directly from the inlet side of the pump into a bucket of water, no issues then it's your suction plumbing.
Good luck,
Ken
 
E

eaststorm

.
Jun 11, 2012
12
catalina 25 4295 mamaroneck, ny
It may be as simple as a defective flutter pump diaphragm. This would allow air to enter the system as the pump does its job,
( to pump water) albeit at less than specified volumes. Also if you have an accumulator tank, sometimes, especially on commissioning, it traps air in its housing. It takes a number of cycles on/off to purge the trapped air from the accumulator tank ( akin to an air lock).
First, do some detective work...... try a short length of hose from the pump inlet into a full 5 gallon bucket. Keep the bucket filling slowly with a hose from dockside water. Turn the system on. See if this eliminates the air/sputtering. If so, it is not the pump.
Then, move backward to just before the strainer ( which is before the pump on the suction side). Maybe it is the strainer or as mentioned in a prior thread, its gasket. Also check the hose connections/ and the length of hose itself, from the tank to the strainer. Sometimes it is best to eliminate as many variables as possible to focus in on the real problem.
Good Luck , and get out cruising!!!!!!!!
 
J

Joe2954

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Jan 22, 2008
169
Beneteau 343 Saint Helens, Oregon OR
My suction leak was at the filter on the suction side of the pump. Also Beneteau ran suction pipe in big loop in cabinet. I taped the threads with yellow teflon tape which helped but eventually replaced the filter, removed the big loop and have not had problems since.
 
CompassRose2

CompassRose2

.
Apr 3, 2013
11
Hunter 31 Portland
I had the same issue. I couldn't track it down. (The air leak) then I remembered that the 1st year I put in the new pump that we had a severe early freeze and the pump was frozen. I had the problem with the pump not shutting off. I was going to replace the pump, so I went Amazon to re-purchase and true to Amazons aggressive sales style they were showing me what others had purchased. One of the items was a pressurized Accumulator Tank. It basically fools your pump into thinking the system is pressurized and the pump shuts off. It actually has a rubber diaphragm in it that is pressurized so it keeps the pressure in the line and the pump shuts off.
Remember my system was doing the same as yours. Would work fine then drew water and air with pump running constantly. Put this magic little $41 tank in line just after the pump, so on the pressure side, and bingo no more air and no more extended running time on the pump.

I strongly suggest checking them out. Even if you don’t really have an issue your pump will run better and last much longer.
 
Neil Spooner

Neil Spooner

.
Oct 24, 2015
32
Hunter 356 Brightlingsea
Problem is going to be in the tank.
Check that the vent is clear (no bugs made their home in the line) which will create a vacuum in the tank and deny the pump water...the pumps are good at pumping, not sucking!
It would be relatively simple to remove the pump and swop the inlet/outlet round to push air the wrong way for trouble shooting at the tank....if you can't hear bubbles coming into the tank when the level is below your limiting level then the outlet pipe at the tank must be connected to a riser of some sort.
Good luck,
Neil
 
W

Wet_Feet

.
Aug 28, 2015
6
MacGregor 26X Calgary
The half full phenomenon may arise if the pump resides at about the half full level. You would have a positive head pressure to the pump above half tank, then it would have to start sucking below half tank drawing air into the system from a leak on the supply side of the pump. I would be tempted to redo any joints between the tank and the pump....or it could be the pump again if the problem went away initially with the new pump. Is there any way to get the pump lower than the tank? This could prove/ disprove the theory.
 
John Gilbert

John Gilbert

.
May 26, 2004
19
Catalina 380 New Castle, NH
One other thing to check - I had a similar issue on my boat and discovered that a manual pump at the galley sink had a crack in the line that fed it. Because that pump was installed between the tank system and the suction pump, I would get air and water together. When I recognized the crack, I shut the valve to the manual pump and the problem disappeared.
 
J

Jeff222

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Jun 8, 2015
26
Oday 222 Tahoe
Take the pump off when the tank is half full, replace it the opposite direction and pump into the tank. You will hear where it leak is .
 
SamLust

SamLust

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Jan 2, 2008
547
Hunter 33 (Cherubini design Forked River, Barnegat Bay, NJ
The aluminum dip tube is pinhole from corrosion where the water level mist frequently sits. Pull the tube out of the tank, you will find swiss cheese. The sides, if aluminum will link similar. I fixed mine with fuel tank slushing compound. Brushed on through an access hole I cut.
 
S

SFS

.
Aug 18, 2015
2,070
Currently Boatless Okinawa
The OP states (in #14 above) that there is no pickup tube. His fitting that supplies the pump is on the bottom of the tank.
 
SamLust

SamLust

.
Jan 2, 2008
547
Hunter 33 (Cherubini design Forked River, Barnegat Bay, NJ
Then he's out of luck. Gotta replace the boat.
 
Ralph Johnstone

Ralph Johnstone

.
Jan 4, 2006
6,479
Hunter 310 West Vancouver, B.C.
SFS said:
Dirty on the inside, or the outside?
Click to expand
On the inside............ of course :snooty:.

We have so much rain here, the outside is always spotless. As a matter of fact, we have so much rain here (how much rain do you ask) that people look like they have a year 'round tan ......... IT'S RUST ! We have so much rain here that people have developed webbing between their toes. And Vancouver is the most beautiful place on earth ........ ON BOTH DAYS IT DOESN'T RAIN !

It's raining here today.
 
JamesG161

JamesG161

.
Feb 14, 2014
7,421
Hunter 430 Waveland, MS
Ralph Johnstone said:
We have so much rain here that people have developed webbing between their toes. And Vancouver is the most beautiful place on earth ........ ON BOTH DAYS IT DOESN'T RAIN !
Click to expand
Yeah that is one more day than this and next year's El Niño.:doh:

By the way...
We have toe webs here is suthin' Louisiana and Gulf Coast.

Difference is we get shrimp, cajun food, and more bikinis in our sunshine times.:biggrin:
Jim...
 
F

FriscoRon

.
Apr 30, 2016
48
Hunter 376 Port of Los Angeles
Pump supply inlet is mounted maybe 2 inches below bottom of tank outlet. I have pex piping and fittings.
Thanks Ron
 
F

FriscoRon

.
Apr 30, 2016
48
Hunter 376 Port of Los Angeles
Bob7307 said:
The fitting at the bottom of the tank that goes to the water system may be clogged restricting flow. Mine was clogged with plastic shavings from original construction.
Click to expand
Bob I will check out clog when I can. Trouble is I'm living aboard full time. I will have to drain the tank. Otherwise water will flood the cabin. Maybe can I can put bowl under it. Or maybe some water will drain to bilge. It's a tight fit getting to water tank outlet. (under forward sleep berth). I may have to cut a new hole in wood panel directly in front of tank outlet fitting. Existing storage hole is to the right. (bad design by hunter).
Ron
 
F

FriscoRon

.
Apr 30, 2016
48
Hunter 376 Port of Los Angeles
2 pirates,
I did assure my stern swim out shower valves were shut. I will check again. Appears swim out shower valves are 4 ft above water pump.
Thanks
Ron
 
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