Air locks

Wesmac42b80

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Anyone have any tips or tricks? Seems like everytime I turn on either my ice maker or salt water washdown - the raw water intake has an airlock. Sometimes it'll burp itself and get going but most times it doesn't. I back feed water through the systems but that only works sometimes too.
Any tips would be helpful.

Thanks Mike
 

Downrigga

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The pump works much better if it is mounted below the water line. The thru hull should be installed aft closer to the keel than the outside of the hull. This should prevent that pain in the ass air bubble.
 

Wesmac42b80

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The pump works much better if it is mounted below the water line. The thru hull should be installed aft closer to the keel than the outside of the hull. This should prevent that pain in the ass air bubble.
Both of those are how and where it's mounted
 

Wesmac42b80

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I am supprised your getting air then. If the hose is also below the waterline the water flow should force any air thru the system and not get trapped.
Yea the pumps and hoses are below water line just outside engine bed stringers. But these 2 keep catching air. No problems with A/C intakes just salt water wasdown and ice maker.
 

Downrigga

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Yea the pumps and hoses are below water line just outside engine bed stringers. But these 2 keep catching air. No problems with A/C intakes just salt water wasdown and ice maker.
So when you take the hose off the outbound side of the pump with it shut off does water come out? Im sure you have checked impeller.
 

xbskt

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The ice maker has a March pump the washdown is a Rule
Teed off the same thru hull?
Any check valves needed?
Maybe one pump is drawing air back through the other instead of drawing water in through the thru hull?
Spitballing here.
 

Wesmac42b80

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Teed off the same thru hull?
Any check valves needed?
Maybe one pump is drawing air back through the other instead of drawing water in through the thru hull?
Spitballing here.
No separate thru hulls
 

chortle

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No separate thru hulls
The March pump is a magnetic drive centrifugal pump, these types of pumps don't suck very well and must be fully flooded to work. As mentioned about the Rule pump, if the discharge port is only an inch or two above the waterline it might be getting air on the discharge side but this is less likely.

There could be a clog or a leak somewhere, likely on the suction side, the thru hull could be clogged or the hose connections on the suction side could be sucking air. Are the hoses old and stiff?

Pull the hose on the thru hull and check for crud, this is the most likely issue since you have two centrifugal pumps pulling water down low with the same problem.
 

Wesmac42b80

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The March pump is a magnetic drive centrifugal pump, these types of pumps don't suck very well and must be fully flooded to work. As mentioned about the Rule pump, if the discharge port is only an inch or two above the waterline it might be getting air on the discharge side but this is less likely.

There could be a clog or a leak somewhere, likely on the suction side, the thru hull could be clogged or the hose connections on the suction side could be sucking air. Are the hoses old and stiff?

Pull the hose on the thru hull and check for crud, this is the most likely issue since you have two centrifugal pumps pulling water down low with the same problem.
No everything is 2 years old. I'll check for leaks though on fittings.
 
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