Air Conditioner people?

[Geek_Guy]

My new to me boat has been displaying odd behavior. We have been on a several day ocean passage. When we pulled into a marina. The AC would not blow cold. We found the strainer was full of junk. Cleaned it and the units came on and did fine all night. Left the next day for an other 2 day sail. The next stop it again would not blow cold. The strainer was OK. Water coming in out of the seacock, and the pump was pushing water. We went to dinner and when we got back the ac started and blew cold all night again. Last stop a day later again no cold air. Left for 1.5 hours, but this time still no cold. Tried the next morning and still no cold.

Had repairman check the unit yesterday. He found no gasket on the strainer which I did notice that last morning. But didn't really think about as when I put it together the days before I was able to tighten it enough for it not to leak. However the last morning it had a drip.

So the question is: Would a small air leak in the strainer cause no water to flow through the AC units. Is there any logic to this condition that after a couple hours at the dock would then allow the flow of water?


I have 2 AC units which is new to me. How does the flow work and when? If one unit calls for water does the water just flow through both units, or is there some sort of mechanism that would allow/block the flow through the shared pump and strainer?

Any insight would be much appreciated.

[Sailmonkey]

If the pump is running water is flowing through both units.

Centrifugal pumps are very finicky about any air in them. It’s quite possible that wave action moved enough water into the pump body to allow the pump to prime.

Fix the air leak and I’ll bet your problems are solved.

[V-Dog]

I'm not an air conditioner expert so enjoy my free advice...

I have one pump running both units on my boat. I had a similar issue as yours, after an extended sail the air conditioner would not function properly when I arrived at a marina. As Sailmonkey suggested, air would get trapped in the pump when sailing so I had to "burp" the sea strainer (by loosing the lid) to get the air conditioner to kick in. I now close the air con seacock when leaving the dock. No issues since.

[Shrew]

Those pumps are not self-priming. A couple of things:

1) IF you turn on the A/C units, but not the pump (usually a separate breaker) it will sound like the until is running, it will be blowing air, but not getting hot/cold and no water discharge on the discharge through-hulls.

2) IF you lost the prime.....same as #1 (Above).

3) IF the pump is pumping, and water is discharging and you're still not getting cold air, then you might have a refrigerant leak.