AC Pump Not Pumping

[High Wire]

When you get some free time open up the suction side of the pump and inspect the impeller and shaft. Sometimes the shaft corrodes badly and the impeller comes loose.

 

[rgano]

Rich, wouldn't it be helpful to close the seacock before you lift the boat so that water doesn't drain out of your intake? Then open it once in the water again.

I have thought of that, and even did it once or twice (I forgot it was closed at least once). However, closing the sea valve while still afloat would leave saltwater in the system. As I am washing the boat down once it's lifted clear of the water, I aim a solid stream of hose water at the air conditioner's exit through hull until I sea freshwater coming out the bottom of the boat at the AC cooling water intake.

Also, along with the other stuff going on when getting back into the lift cradle, including getting pax off the boat along with whatever gear they brought, going down under the companionway steps and reaching in to get the awkward ball valve handle turned is an additional sweatex I don't want. Getting the engine and generator freshwater flushed and all the cushions and other paraphernalia stowed is a minimum half hour project until I can get out onto the pier for washdown of the boat and sometimes me as well.

The bleed valve is in very easy reach and and is a positive indication of success in de-bubbling the system. I don't even have to go forward and lean way over the rail to see the confirm a stream of water exiting because I see it at the bleed valve with its 1/2" clear PVC hose squirting a solid stream of water into the bilge for a few seconds until I shut it off. Altogether, the optimal solution to my situation which took several years for me to finally come up with.

 

[ronobrien]

Hi there,

We have four HVAC units on board that are provided water from one pump. Two days ago I noticed two of the HVAC units were not putting out the usual amount of heat (I usually one use those two units). This morning I realized there is no water circulating. I verified the strainer is clear, seacock is open and the is water coming in (I tested it).

The pump goes on, but no water comes out and two of the four HVAC units will not cycle on (they are new this year). The pump sounds like it's pumping but no water comes out. The pump is below the water line by at least 18".

Any thoughts about next steps?

Thanks - JimLView attachment 134466

Check that those 2 pumps haven't lost prime somehow. Those A/C pumps are centrifugal and not self priming. That is why they need to be below the water.

 

[jimL]

I have never have this happened. My guess is that the air got into the system when I cleaned the strainer and I didn't notice the effects till a few days later. It was cool outside so we left the ER doors open to heat the boat.