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edbulmer · 12-01-2013, 19:26

I am in salt water, I have marine air units. I have noticed that there are two water outlets, one has a large flow and the other has a small flow. Is the one with the small flow just a back-up in case the other gets blocked? It seems to just trickle out of that onel. I was told that bromide tablets aren't necessary, should I be using them. I did clean out my strainer and it seems to be better.
Any ideas are welcome.

Sailorman375 · 12-01-2013, 19:34

DO you have two units and two pumps and two strainers? You probably do and in that case each will need sufficient flow. Might have to clean out the hoses as well as the strainers. Bromide helps if you get lots of growth.

motion30 · 12-01-2013, 19:41

I have two units and two outlets but just one pump. One does flow more then the other but not much

edbulmer · 12-01-2013, 20:33

I have 3 units. They all flow through one strainer. All 3 get great flow from the main throughhull but the one small throughull has a much smaller hole and I can't figure out what it's use is. Just a small amount of water comes out of that one.

DeepFrz · 12-01-2013, 21:10

Is it a condensate drain?

sailorboy1 · 13-01-2013, 04:22

Quote:

Originally Posted by edbulmer

I have 3 units. They all flow through one strainer. All 3 get great flow from the main throughhull but the one small throughull has a much smaller hole and I can't figure out what it's use is. Just a small amount of water comes out of that one.

Are you saying the outlet6 from 1 unit is smaller? In which case I bet that AC unit is smaller capacity and it has less flow because it has smaller cooling tubing.

Blue Stocking · 13-01-2013, 05:04

Water will take the path of least resistance, shortest distance, if all outlet heights are similar. There may be a flow control valve somewhere, to balance the distribution?

waterworldly · 13-01-2013, 05:30

My advise would be to disconnect the output from the suspect AC unit and hook a hose to it. If it flows free, then the possible blockage is between your pump and the AC output. In that case, hook a regular garden hose to your outputs from both machines, run it back to a bucket full of water/Barnacle Buster mix. Run a third hose from the bucket to the input on your AC pump and let it run the loop for about 4 or 5 hours. If the flow gets better, you win. With this method it will be easy to see the output from the suspect AC and if it gets better. I know this sounds a bit complicated, but it's not. Just buy a cheap garden hose. I did it for three units and it worked like a charm. It was also a lot better than doing one unit as a time, as you do all of the supply lines as well.

jeremiason · 13-01-2013, 06:57

This could be MAJOR problem... As stated above water will take the path of least resistance.

I have three factory installed Marine Airs units on my boat... Two of them are on one water pump and the third has its own pump. All of them are run on 1/2" water lines and none of the untis have a "back-up water line".

Several years ago the water line plugged in the two unit water intake and I fried one of the AC units from lack of water flow. I had the same symptom as you... one flowed normal the other flowed at a trickle.

It turned out a critter got behind the intake grate and grew large enough to obstruct the intake of salt water to about 50%. The unit with the least head pressure got the majority of the water flow.

Check the the salt water system from the intake, including the raw water filter, the plumbing and the outbound through hole.

My guess is you have an obstruction somewhere....

edbulmer · 13-01-2013, 06:59

Before I do this I want to make sure I was clear. I have 3 units and 4 through- hulls. The 3 main through-hulls all flow fine, they are like Niagara falls. But there is this fourth one that is smaller and has a small flow and it is on when any one of the other units is on. I'm trying to figure out what that is. If it's a by- pass or over-flow etc. And if it should be reallly flowing (like the others) or if it's okay that is just has a small flow. (I did put some acid through the system and clean out my strainer). And do I need bromide tablets?

jeremiason · 13-01-2013, 07:17

OK now it is becoming clear...

Trace the water line from the outbound thru hull that is runningat a trickle back to the units...

My guess is they tied the drip trays that thru hull.

My AC unit's drain to the bildge and normally produce about 3 or 4 gallons of water per hour from the drip trays, probably more down here in the tropics.

transmitterdan · 13-01-2013, 07:36

Quote:

Originally Posted by edbulmer

Before I do this I want to make sure I was clear. I have 3 units and 4 through- hulls. The 3 main through-hulls all flow fine, they are like Niagara falls. But there is this fourth one that is smaller and has a small flow and it is on when any one of the other units is on. I'm trying to figure out what that is. If it's a by- pass or over-flow etc. And if it should be reallly flowing (like the others) or if it's okay that is just has a small flow. (I did put some acid through the system and clean out my strainer). And do I need bromide tablets?

There are venturi devices that will suck the water out of the drip pans. They are pretty much the same thing that is used to drain the water from a water bed. These are usually installed in the outlet water line with a tee in the side and a small hose to the drip pan. Usually they do not need an extra through hull. It could be that someone installed a separate line just for this condensate removal device. It might flow less water than the main coolant lines since it isn't actually cooling anything. Try to trace the hose from the slow flowing through hull back toward an AC unit. If there is a funny looking TEE in that line then it is probably the condensate drain device. If so then it may connect to all of the A/C evaporators to suck out the condensate water.

If your 3 outlets have full and equal flow then probably everything is as it should be. The best advice I have received is don't start fixing something unless you are sure it is broken. I think that applies here.

Best regards,
Dan