410 Sundancer A/C / Heat - Water Discharge Issue

THJeff

THJeff

Active Member
Jan 4, 2012
278
Lake St.Clair - Michigan
Boat Info
2000 410 Sundancer
Engines
CAT 3126 Diesels
When I tried running my heat / A/C for the first time this season, I encountered some problems. Both the salon and forward stateroom compressors/blowers run fine, the water pump is running and the sea water strainer is clean but no water is coming out of the discharges on the starboard side. This results in the heating system running for a few minutes with the compressor on, but then it cycles off with very little warm air being generated. I tried running the A/C briefly as well and encountered the same result. Obviously the fact that nothing is coming out of the discharge is the problem. I don't think anything is blocking the intake on the bottom because when I open the strainer in the bilge, water spews out like a geyser. For some reason, it seems like the pump is not getting water through the system but the pump is definitely running. Absolutely no water is coming out of the discharge so I don't think any of the lines are leaking and it is very unlikely anyway because my boat was in warm storage all winter so there are no winterization issues. The system is a Cruisair SMX II and the forward stateroom thermostat reads "LO PS" which I interpret as low pressure, but I'm just guessing. This is my third season with this boat and I've never had a single problem with the A/C / heat. Does anyone have any ideas what the issue could be before I call for service?
 
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Someone I knew had the same problem. It may be that air got into the system. I remember a friend telling me that he took boat for a ride after winter storage, the problem went away. Good Luck!
 
Thanks Mario. The boat splashed on Thursday so maybe air in the system is the culprit. We are planning on going for a ride tomorrow so hopefully we have the same luck. Fingers crossed...
 
Seacock open ? Or take hose off outlet side of pump, let water flow thru,
 
You can force feed it from the water outlet. You might get wet though :) Just push a hose in the outlet and turn on the water....
 
I was surprised to see that there is no seacock. The hose just comes up from the bottom of the hull and into the strainer. When I open the strainer, water gushes out so water has to be coming in. It seems like the pump may not be pumping it from the strainer to the compressors. But the pump is running so I'm stumped.
 
THJeff said:
I was surprised to see that there is no seacock. The hose just comes up from the bottom of the hull and into the strainer. When I open the strainer, water gushes out so water has to be coming in. It seems like the pump may not be pumping it from the strainer to the compressors. But the pump is running so I'm stumped.
Click to expand...

A/C pumps can't run dry (they are not self-priming) - which is why you need to "manually" prime it.

But I would get a seacock in there for safety...
 
kaz911 said:
A/C pumps can't run dry (they are not self-priming) - which is why you need to "manually" prime it.

But I would get a seacock in there for safety...
Click to expand...
Yes, it's as if the pump needs to be primed. I've primed many swimming pool pumps but I have no experience with one like this. For one, it's much smaller and like I said, water is flowing up to the strainer so water is right at the pump but it's not flowing through. Any suggestions on how to manually prime this pump?
 
Jeff,

There are three easy ways to prime it:
1. Go out and run on plane - that will force water into the inlet and pump.
2. Put a hose against the discharge port and force water in backwards flow.
3. Run the pump and unscrew 3 of the four screw around the pump housing. Loosen the fourth screw and the air will bleed out.

I have used all three methods with success. Ensure your intake grate is not clogged with sea grass.

Are you certain you dont't have a sea cock? That would be the very first thing I would have done before you splash. Sea Ray would have put one in, so someone must have removed it. It is extremely dangerous to operate without one.
 
THJeff said:
I was surprised to see that there is no seacock. The hose just comes up from the bottom of the hull and into the strainer. When I open the strainer, water gushes out so water has to be coming in. It seems like the pump may not be pumping it from the strainer to the compressors. But the pump is running so I'm stumped.
Click to expand...
There is a sea clock for that strainer.
 
Mine did the very same thing, so I "primed" it by forcing water thru both outlets. That did the trick. Only weird thing is now I have water coming out both outlets whether one or both AC units are on. Not sure it did that before.
Strange and disconcerting not to have a seacock for cleaning strainer or if you ever blew a hose and needed to stop water flow...
 
carterchapman said:
Jeff,

There are three easy ways to prime it:
1. Go out and run on plane - that will force water into the inlet and pump.
2. Put a hose against the discharge port and force water in backwards flow.
3. Run the pump and unscrew 3 of the four screw around the pump housing. Loosen the fourth screw and the air will bleed out.

I have used all three methods with success. Ensure your intake grate is not clogged with sea grass.

Are you certain you don't have a sea cock? That would be the very first thing I would have done before you splash. Sea Ray would have put one in, so someone must have removed it. It is extremely dangerous to operate without one.
Click to expand...

Thanks very much Carter. We plan to go for a ride today so hopefully it will prime when on plane. I thought of the reverse prime you suggested but I'm not going in this freezing water to stick a hose in the discharge.
As for the seacock, I see no kind of valve unless it's somewhere on the strainer. The boat only had one previous owner, an old lady who hired a captain to drive so she doesn't seem to have been the type to tinker around with such things. It's a mystery to me where it is. Perhaps you could take a picture of yours whenever you have a chance and post?
 
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