Losing prime on seawater pump

[betzhunter]

I must have a real old ac system that works flawlessly but I can't seem to find anything about it on the net. the control panel has "Neptune Marine Air" stamped on the front. My question is: sometimes I lose prime from the pump after returning from day out on the water. Then I have to manually force water in from the hose to get the pump to prime. This doesn't happen often. I did notice that when I turn the knob to fan it doesn't start the pump not until I rotate it to AC does the pump come on.
This might be correct because it is an older unit ??? Not sure? It is a 16,000 btu unit. If anyone has one like it or can shed some light on what I should do please chime in. I've enclosed pictures of the panel and the back of the control knobs.

Thanks ,

Follow up to this post: I guess I was really looking for anyone that has had this system on there boat and could shed some light on the wire diagram that might lead me to finding if these knobs are wired correctly. I'm sure the newer models ac systems when the knob or if digital is set to fan the sea water pump would come on together. Mine does not. It comes on when the ac is turned on. When it's not primed the ac will kick off. Looking for some help with the wiring setup on the supplied picture.

Thanks

Bub

 

[PKFK]

Sometimes heeling will cause the pump to lose prime - most of these are not self-priming.

I had this problem as well - easy solution was to just close the seacock unless using the system. (You DO close all those when sailing anyways, right ?)

;-)

Paul

 

[betzhunter]

Sometimes heeling will cause the pump to lose prime - most of these are not self-priming.

I had this problem as well - easy solution was to just close the seacock unless using the system. (You DO close all those when sailing anyways, right ?)

;-)

Paul

Yes all are closed except freshwater for engine.

 

[betzhunter]

Follow up to this post: I guess I was really looking for anyone that has had this system on there boat and could shed some light on the wire diagram that might lead me to finding if these knobs are wired correctly. I'm sure the newer models ac systems when the knob or if digital is set to fan the sea water pump would come on together. Mine does not. It comes on when the ac is turned on. When it's not primed the ac will kick off. Looking for some help with the wiring setup on the supplied picture.

Thanks

Bub

 

[kloudie1]

Hey, Bub.. my unit has electronic controls but I have worked on units with manual controls and the "fan" position on the switch does not turn on the water pump. A 120volt jumper with a switch could be made up to run the pump manually, which would help with getting the thing re-primed.

EDIT: might be pretty easy to put a switch in the power wire to the compressor so that when you turn the switch to "COOL" the fan and pump would run but not the compressor unless that switch were flipped ..

 

[betzhunter]

Hey, Bub.. my unit has electronic controls but I have worked on units with manual controls and the "fan" position on the switch does not turn on the water pump. A 120volt jumper with a switch could be made up to run the pump manually, which would help with getting the thing re-primed.

EDIT: might be pretty easy to put a switch in the power wire to the compressor so that when you turn the switch to "COOL" the fan and pump would run but not the compressor unless that switch were flipped ..

Hey Claude, I'll have to think about that for the switch. I see your marina is completed, we drove by there Thursday. It was nice meeting and talking to you face to face instead of internet to internet! Also, thanks for letting me take photos of the head seat area so I could duplicate it, I did complete it and installed it.
Thanks Bub​

 

[kloudie1]

Wow.. Looks fine, Bub.. Yep.. it was good meeting and visiting and talking boats.. I am back in Mandeville.. I was there Tuesday and again Friday, tieing up for the little storm..