CruiseAir Countdown?

[stormchaser]

So, need AC for the first time this year. Took the boat out yesterday and had a nice ride. Whenever I get back from a ride, getting the pump to prime has been a pain. I have to open up a priming spigot FAST, get it primed and close it before the unit shuts down. I usually have to do this maneuver several times before it starts to work right. Well, the unit in the salon wont stay on. it runs (and generates cool air) for about 30 seconds then shuts down and the display starts a 90 second countdown then it tries again. And the unit is HOT to the touch. Seems like it might not be getting cooling water flow? Does that make sense? The forward unit, the guest stateroom and the aft seem to be fine...just not the salon. Should I let it thoroughly cool down for a couple hours before trying again? Any other thoughts? I seem to have good water flow...the other units seem fine...

 

[stormchaser]

OK, panic averted. I needed to run all the other units for a while to get the air out of the lines and let the salon unit cool down. Seems to be working fine now. PHEW!

 

[wshelton]

I got a new problem with my cruise air system on my 43' Hatt. Aft system is independent. One compressor, two coils and fans in each cooling aft cabin and forward cabin. Aft cabin coil and fan work okay. Forward system will work on initial start up and run for short while and shut down for no apparent reason.

Must be in coil and fan? Could it be in the 3 knob control unit, old style controls?

 

[34Hatt]

If its a pain why not just fix it by relocating the pump!

I never even prime mine after being out of the water for the winter.

 

[REBrueckner]

On the first issue: just lookover the side and see if water is exiting the system. the centrifugal pump is normally located below the water line so it should pick up water immediately...should not need to priming...

On the second post: forward system shuts down....this means the fan shuts off based on your description...which might mean the thermostat is not working properly...or maybe a loose connection in the controls...

 

[TopHattandTails]

I'm still trying to get past the "I took my boat for a spin today" comment. Only 28 more days 'till splash down! Still need to get winter 2010 work completed, canvass, and varnish done. Really looking fwd to this year! Anyone on the Atlantic need a great Commercial Real Estate guy? Willing to relocate for winters aboard! Good for you guys running the boats.

Signed,
jealous in Cleveland.

 

[spcoolin]

First problem....As others have said, the pump should not need priming although on the 53 it is close to the water line...If there are any dips or loops in the plumbing they will trap air and cause the need to prime.

It also should not need prime after a run...If it does, I would look for a loss of the fwd facing scoop that should be over the thru hull on the bottom of the boat...Without this scoop, any speed over about 6-8 knots will cause the water to be sucked out of the pump when underway...Thus the need to re-prime.

Second problem...Sounds like the Fwd fan has been wired to the pump or compressor wire...Actually it started out life wired to the pump, but if someone has changed the wiring to run the pump only with the compressor it will cause what you describe...Compressor cycles off on the T-stat & so does the fwd fan...Originally the pump ran anytime the fan ran...24/7...Now many have been changed to the compressor circuit to reduce pump run time & the frequency that the strainer needs cleaning.

Steve~

 

[SKYCHENEY]

I have a similar priming problem on my 53. I have rebuilt the pump but it still takes time to pick up. It pumps a weak stream for about 5-10 minutes and then it gurgles and starts shooting out like it should. The scoop is in place so I think it may get bubbles in there off of the stabilizer fin when running. I don't know, but it really makes no sense as the pump is below the waterline.

 

[spcoolin]

Sky...Are you seeing bubbles In your strainer when it happens ?
If so...You are sucking air, and it's likely from one of the gaskets of the Perko strainer...Also if the cover wingnuts are not tightened exactly even it wil suck air there & cause the pump to cavitate.

Steve

 

[67hat34c]

If you have to prime the pump and it is not a self priming pump then your plumbing has issues. Means you have dips in the hose or high spots in hose between pump and the units and/or there is a clog of some type. Air pockets will prevent water flow. Even a small dip or raised part will cause this. Prior owner of our boat told us that you have to prime the pump every time you use the boat. I did a little research and then made plumbing corrections and it was find from there forward. Only one I could not resolve was the head so I went with self priming pump there and problem fixed.

Have you acid washed the system lately?

 

[stormchaser]

I'm fairly certain I do NOT have a forward facing scoop for the intake...that will be addressed at next haul out. But I'm glad to know other 53 owners are experiencing it too. All seems fine now that the system has purged all the air out. I just need to remember to run the other units first to help get the air out and the pump fully flowing before starting up the big salon unit.

 

[SKYCHENEY]

Sky...Are you seeing bubbles In your strainer when it happens ?
If so...You are sucking air, and it's likely from one of the gaskets of the Perko strainer...Also if the cover wingnuts are not tightened exactly even it wil suck air there & cause the pump to cavitate.

Steve

No air bubbles in the strainer. It's not a big deal. I just turn on the little 6K unit until it primes completely and then it's good to go. Just a annoyance.

 

[spcoolin]

Guys...It makes no difference what unit you start first because once the pump starts...It pumps thru ALL units...(providing the pump is primed)

That is unless you have a bad trigger in the pump relay that is not telling the pump to start for any particular unit.

Simple test for that is start each system alone to verify pump start...Meaning with no others on..Start one system...If it starts the pump, shut it off & start another...If each system starts the pump...No troubles...But if one or more does not start the pump...That or Those systems will only get seawater when the other units are calling (ones that will start the pump)

Steve~

 

[stormchaser]

All my triggers work fine and the pump turns on with all units, and I know water flows through all units, but it seems like the little units don't shut down as fast due to the reduced water flow due to air in the lines...the big one shuts down much faster. If I run the smaller ones for a few minutes first to get the water flowing without bubbles, then the big one is fine. If I start it first, it shuts down and gets REALLY hot. Problem does not happen if I run the smaller units for a while first. SWtrange I know, but also my reality. haha!

 

[Pascal]

you should not have to prime an AC pump if installed properly. the key is to have an uphill run from seacock/strainer to the pump inlet with no high or low points.

on the earlier 53, the pump was installed outboard of the shaft/tranny and very hard to reach, with a longer hose run. I finally relocated the pump right behind the aft door, on the stringer. it's still below WL and very close to the seacock, under the port shaft. no issues.

first thing is to check outside for discharge although this doens't guarantee you have flow too all units since they all come out of the sea chest. if you suspect reduced flow on one unit, all you have to do is disconnect the discharge hose off the sea chest and compare flow. easy to do.

if one has less flow, check the hose and manifold which splits the flow to the 4 or 5 units for blockage in one branch. try backflushing that line to dislodge an errant barnacle. don't you have issues with jelly fish or nettles in the Chessie? coudl you have some critters styuck in tthere? when is the last time you had the coils cleaned?

 

[SKYCHENEY]

Guys...It makes no difference what unit you start first because once the pump starts...It pumps thru ALL units...(providing the pump is primed)

That is unless you have a bad trigger in the pump relay that is not telling the pump to start for any particular unit.

Simple test for that is start each system alone to verify pump start...Meaning with no others on..Start one system...If it starts the pump, shut it off & start another...If each system starts the pump...No troubles...But if one or more does not start the pump...That or Those systems will only get seawater when the other units are calling (ones that will start the pump)

Steve~

Steve,
That is not the case. My pump will provide limited flow for the first 5-10 minutes before it really takes off and pumps. If I look at the outlet, I see a trickle and then I hear a gurgle and it really shoots out.

The only unit that will not go into high temp shutdown when the low flow is running through is the mid cabin 6K unit. The pump will run with any of the 4 turned on. This is not a trigger issue. It is a flow issue.

The pump has a manifold on top of it that splits the water to four hoses, one to each unit. I think that when it is under low flow, it only runs water through the hose with the least resistance and the other three get no water.

It is very strange and I have crimped off hoses to try to see if it will "prime" quicker but to no avail. I have rebuilt that Oberdorfer pump with all new impeller and seal and that didn't help. Once it picks up and runs, it is fine until the next time the boat is run.

 

[spcoolin]

I'm not doubting what you are saying is happening but I wanted to eliminate what I described first.

If you have no scoop..I can see what you are describing happening...Especially on a 53MY that has the pump so close to the waterline....
Still...Even in the original installation...It should pick up prime when the boat is at rest...Relocating that pump can help & Pascal is right...Continuous uphill with no dips or loops is key...

I would also consider getting rid of that Oberdorfer & going with a magnetic drive March pump...No shaft seals to leak or suck air, and an impeller that does not wear out like in the Obies.

Seems when I replace a Obie with a March...I never make a dollar on that customer again...At least pump related...They seem to last forever.

Steve~

 

[hatteras36]

try the reset button my unit has one

 

[SKYCHENEY]

Steve,
I think the pump is the problem. I put the new impeller in but the pump body itself may be worn to the point that it just does not pick up like it should. It appears to be the original Hatteras setup and the original pump and hoses.

 

[Canuck Dennis]

With a multi take off type header on the pump, you have to be sure that equal flow goes to each line, there is a specific way to pipe that arrangement so that all flows are equal.