A/c pumps replaced

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JEP

Veteran Member
Joined
Oct 28, 2014
Messages
25
Location
USA
Vessel Make
34' mainship motor yacht
Last summer I replaced my front air with a marine aire system, I also replaced my water cooling pump with it with a 500gph. The old pump handled front and rear air. This was original equip (1997 ). The marine aire sales man said it would not handle both units so I put a y on the water coming from the thru hul (3/4") and put 2 -500 gph pumps. I cannot get one pump to draw water even after priming. My question is, the tru hull is 3/4 so can that provide enough water for both pumps? Or is one pump bad? The one that want prime, gets very hot. I wired both pumps together, so I assume both pumps will run when either unit calls for water. Today my old a/c unit keeps,kicking the breaker so I assume it's going out now. Help need advice
 
Either go back to having one pump that can handle both units or plumb each pump with its own seacock and strainer. The pumps should not be wired together.

As to the pump getting hot, it's either not getting cooling water throught it's motor body, assuming its a March pump, or the impeller is jammed. Open up the wetted end and see if there is a problem.

Quite frankly based on what you've done so far and the questions you'd asked, you should consider getting an A/C tech to help you out.
 
Hook up the suspected pump on its own (water and electric) and see if it operates correctly, if no then defective pump, if yes then do as Capt Bill11 states above^
 
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Marine aire did not have a pump big enough in stock so they recommended to do this. I thought 1 big pump would be better. My boating buddy's said it has worked on 1 500 gph since 97 and should work again. My reply was that the new unit calls for 500 by itself and I did not want to burn up new AC
 
We've been running 2-1600 BTU units from 1 March, AC-5C-MD 115 VAC for 6 years with no issues. Its rated for 900 GPH at 6' head. If you don't like March, Oberdorfer makes a good pump.

Maybe sell the one you have and put it toward a new pump or tell your AC guy to take it back. :) The March pump referenced above is less than $275 delivered.


http://www.ebay.com/itm/March-pump-...778?pt=LH_DefaultDomain_0&hash=item5418d7a5fa
 
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I think the problem I have is, it is only 500 GPH. Whats your thoughts, pull it off and start over with the March 900 GPH or run the 500 GPH to see if it can handle it?
 
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