Is my freshwater pump too small?

RobWales

RobWales

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21 Sep 2006
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Gran Canaria
www.3ksengineering.com
Hi All,
Sunseeker portofino 34 1991
I have 4 sets of taps,one on swim platform,one on cockpit wet bar,one on galley and the last in the heads.
My water runs extremely slow with low pressure, I have checked the pump and I have no leaks etc and it does shut off when getting back pressure when the taps are not running.
Also in the circuit is an accumalator tank though not very big!
Pump is a 2.5 gpm
Is this too small and what size should I be looking at?
For what its worth this pump does not look original.
Thanks and happy new year to you all.
Rob
 
unlikely that all outlets will be in operation at the same time, but I'd guess a 16litre/min would serve you better. The pressure should be 20/30 psi (on/off).

The size of the accumulator doesn't really matter too much, so long as it does its job of evening out frantic on/off of the pump.

There may also be a constriction or kink in the pipe work near the pump; can be checked quickly by visual inspection. It is also not unknown for a valve / tap in the output circuit to be partially closed (/forums/images/graemlins/grin.gif).

I'd guess that Jabsco will advise; their tech help people are mustard.



pump clicky
 
Thanks,
Had my head in the pump compartment today and cannot see any kinks etc and as far as I can tell I have no other taps/valves in the outlet side that may be partially shut!

I was thinking that perhaps a 17lpm would be better suited especially as there are a few on that auction site at a very good price!
 
[ QUOTE ]

Pump is a 2.5 gpm


[/ QUOTE ]
I think domestic power showers are about 12 litres/min so the spec of pump is correct. Suspect your pump is dodgy or a kink (I know you've checked for that) Careful with over specing the pump, with small sinks you could end up with splashes everywhere.
 
It sounds like a restriction in the system to me. Do all outlets have this problem?

Have you checked the filter?

The system pressure will rise and equalise and turn the pump off, but when you open a tap upstream of the restriction, the pressure sounds as if it is dropping fast in that part of the system. The low flow may be due to the high pressure side pushing water past this restriction.

Of course once you close the tap, the pressure will slowly equalise again.

The pump on my boat starts fairly quickly as soon as a tap is opened. Yours should do the same. A delay may indicate some form of restriction, unless of course the pressure switch just happens to be upstream of the restriction then it may cycle on/off frequently even with a low flow!

On my Fairline Targa 34 (similar size to your boat) my Sureflo pump serves: a shower/WC/basin, kitchen sink, aft cabin basin and deck shower - it provides 2.8 GPM at 20psi and it all seems fine. Excellent pressure when using the shower!

I would have thought 1 Bar (14.5psi) is more than enough at outlets, so a pressure setting of 20psi should be fine.
 
Just got back from the marina....
Checked filter........clear
Does pump come on as soon as tap turned on......Yes
Switch off as soon as tap turned off........Yes
All taps slow with p**s poor pressure.....yes
Kinks in pipes.......(removed carpets today ready for new) so was able to access all areas( well most) kink free!
My guess is that my pump is sha**ed?
Anyway for the price they are on ebay I think I will fit a new one and hope that cures things.
Thanks for your input.
Rob
 
Mmmmm, I would probably do the same!

There are ways of checking, taking water pressure readings and running currents but could waste a lot of time!

As is often the case - a process of elimination: pump, pressure switch, etc.

Best of luck and do let us know how you solve the problem!
 
UPDATE
Fitted my new 17lpm pump today and hey presto I have niagra falls at every outlet (when turned on of course)
Result.
/forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
 
Nice one, pitty ya couldnt take a vid of the before and after to show the difference.

Actually, prob best off you didn't as i'd prob want a bigger pump. Nothing wrong with the one I have, but I wouldn't mind a power shower out on the transom /forums/images/graemlins/smile.gif
 
[ QUOTE ]
alt,
To give an idea of the before scenario.....
I couldnt even get the transom shower to dribble!
Now I can soak the boat on the opposite berth. /forums/images/graemlins/grin.gif

[/ QUOTE ]

Ah, OK, gotcha. Just as it should be now so. I get plenty of pressure on the transom shower, plenty enough to have a nice wash off with warm water when done swimming etc.

Glad you got it sorted. Can I be rude and nosy, and ask how much the pump cost?
 
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