A/C pump

trailshredder

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What a way to start our 4th weekend. Got to the boat and discovered someone hit the starboard side rear of our boat and took a nice chunk of gelcoat off, down to resin! Fired up the A/C because it is in the 90's in Ohio. The pump seems weaker than normal and the pitch changes as it is pumping. Getting a good stream of water though. Strainer is clean and good flow of water coming into the strainer. Likely time for a new pump?
 

Scott Danforth

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when was the last time you replaced the impeller on the AC? they need regular service
 

trailshredder

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We have had the boat for 5 years and have done nothing to the a/c. Showing my ignorance, I did not know the ac system had an impeller. Where is that generally located? The pump did start sounding better and got us through the weekend but gets pretty hot when running. It appears to be the original 500 gph pump.
 

alldodge

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Most the impellers in the AC pump last a very long time in fresh water. Many have trouble priming which if that's the reason there are easier fixes. Like use a shop vac to suck water thru from the discharge port

The pump is normally in the engine room down low
 

mr 88

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Start at the Ac unit where the water hose enters and backtrack it , will lead you to the pump.
 

trailshredder

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Sorry, didn't explain myself thoroughly. I have located the pump, I was confused where the impeller is. Now I understand it is in the pump. Lol Should the pump be hot or is this a sign of a failing pump?
 

mr 88

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Hot is probably a sign of a failing impeller , not enough water going through it. And if the impeller is missing fins you may want to try and track them down. They will impede your flow and clog things up.
 

alldodge

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Sorry, didn't explain myself thoroughly. I have located the pump, I was confused where the impeller is. Now I understand it is in the pump. Lol Should the pump be hot or is this a sign of a failing pump?

If water isn't flowing it will heat up, but as before may just need to use a shop vac to get it started. Others take it out for a run so water is forced in the pickup
 

trailshredder

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Hot is probably a sign of a failing impeller , not enough water going through it. And if the impeller is missing fins you may want to try and track them down. They will impede your flow and clog things up.

So can the impeller be serviced/replaced like a raw water pump impeller or do you replace the entire pump? Hoping to pull the pump this weekend.
 

mr 88

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You should be able to replace the impeller . See if you can find any identification on the pump. That will help you to track down a impeller. If there is no ID after pulling the impeller I would try to match it up. Google ect will be your friend for that. First start out with the AC mfg , then try impellers for marine AC water pumps . Also try ebay and Amazon . Should have a flat surface /slotted or splined to lock it in place on the shaft. Sometimes if you have that info and the diameter of the impeller or housing you can cross reference it with a generic one. In most cases the impeller will be used for something else as well , Pump mfg tries ti keep overhead down for production so they use as much off the shelf material as they can, including O rings , washers, motors ,shafts and impellers.
 

alldodge

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AC impellers do not make direct contact with the pump housing, so there is next to no wear in fresh water

Many systems develop algae inside the AC coils and this is what causes system to loose flow and also cooling power. May just need the coil and lines cleaned
 

trailshredder

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AC impellers do not make direct contact with the pump housing, so there is next to no wear in fresh water

Many systems develop algae inside the AC coils and this is what causes system to loose flow and also cooling power. May just need the coil and lines cleaned

Is cleaning the lines a DIY or is special equipment needed?
 

alldodge

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Is cleaning the lines a DIY or is special equipment needed?

Should not be a problem. Take a bucket and small bilge pump. Mix muriatic acid 1 part to 3 parts water. Start and let it run for a couple hours.

Plug the over board hose and fill with solution for a while and let it sit. Then flush with hose and reconnect

Or can use this method, but will take more gallons
 
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