Cruisair water flow problem

[mrfordsr]

I have a 2001 50' Gibson with two separate cruisair a/c units. The cooling water outflow on one has decreased to about 60% of the other one. The unit with the lower flow runs briefly and cycles off, shows a "high pressure" message on the control panel, cycles two more times with the same message and then shuts down. I have cleaned the strainer. That did not improve the outflow. Do I have an impeller problem? If so, can I replace the impeller or should I order a replacement pump? I am a novice large boat owner. I would appreciate any advice. This is my first post.

[AnchorageGuy]

You either have a bad pump or the lines are obstructed. You will need to blow our the entire lines and try hooking up the working pump on the non working line to see if the results are the same. That will give you a good idea of what the problem is.

[Pblais]

The Hi pressure alarm is what happens when it does not get enough flow. It overheats then shuts itself down so the good news is the unit sounds fine. It's supposed to do that rather than burn itself up and it should not have any damage.

Something that happened to me was a lot of growth at the through hull. So you might want to check to be sure you have a good flow at the through hull. I've done things where I would disconnect the supply to the pump and connect it to a garden hose and use the city water pressure to blow it out. That works a little bit but usually means there is another issue with growth or the pump.

If it is just a flow issue then I would ask what type of pump you have. If it's the one with a silver body then it probably is a Cal pump - they are terrible. They eventually fail and can not be repaired so don't try. You would do better to get a March pump. Yes, they cost more. They have a separate pump head all nylon and you can replace the head for about $70 instead of the whole pump. Try to keep the salt water line as short as possible since you can get growth in the lines and just has more resistance. If the line is just too long then you would need a bigger pump. Don't forget the outflow too. restricted outflow is as bad as restricted in flow.

[cabo_sailor]

I'm not getting flow on my a/c at the moment. This is a fairly common occurrence here in the warm water of Florida and as Pblais states it's usually an obstruction. Simply cleaning the strainer has never been enough to get mine working again and I usually end up connecting a garden hose with an appropriate size nipple to the lines to "blow" them out.

However, one time I found the problem to be corrosion on the power leads to the raw water pump. I went to check voltage going to the pump and while jiggling wires one came right apart. A few minutes worth of repair and I was good to go. The corroded condition of the power lines reduced the voltage to the pump so that while it pumped, it was not putting out the volume that was needed.

As a question of mine own - would it damage anything to connect the garden hose to the downstream end of the strainer and use it to flush water through the a/c? I've hesitated to do so.

[AnchorageGuy]

cabo, we do it all of the time although usually after the strainer and sometimes reverse from the discharge. You get more pressure not going through the strainer and just clean it separately.

[Pblais]

As a question of mine own - would it damage anything to connect the garden hose to the downstream end of the strainer and use it to flush water through the a/c? I've hesitated to do so.

Nope you can turn down the pressure at the faucet and then you don't need a pump. Adjust the valve until the flow is right. Makes for a big water bill though.

Better to dive the boat and double check the through hull for growth.

[AnchorageGuy]

Paul, I think he was referring to just flushing the system. You are correct that it will use a lot of water to run it that way.

[speciald@ocens.]

I use a piece of water hose with garden hose attachment to flush my system. I had a problem with one unit last week. Had a diver clean the thru-hulls - problem gone. He said there were Zebra muscles in the inflow. When I lived in Florida on the St. Johns River,I had a constant problem with eel grass clogging the strainer and the intake. I had to blow out the system weely in the Summer. You probably have a pump with a magnetic impeller. Any crap that gets to the impeller will stop the pump cold.

[Latitude9.5]

Just got done cleaning the creatures out of my a/c strainer, you wouldnt believe how quickly they fill up.

[S/V Antares]

The lack of cooling water can also make a lot of heat before the unit shuts down. Be sure to inspect the hose from the pump to the AC unit. High heat can collapse the hose restricting the flow even after replacing the pump.

[cabo_sailor]

Paul,
I was just going to use it to flush the system. I was just not certain if there was anything that could be hurt if the pressure was more than what the pump normally provides. Especially the pump which in my case at least is a magnetic.

The way the thing fills up with crud sometimes makes me wish I had the old hatch cruiseair again. Too bad they're not powerful enough for my size cabin and take up so much space.

[Latitude9.5]

I have a pretty large strainer on mine, I have dropped a couple of the algae tabs in it in the past, the same ones you buy at home depot to drop in your a/c drip pan. Seems to clean out the lines i can see through anyhow.

[Pblais]

I was just not certain if there was anything that could be hurt if the pressure was more than what the pump normally provides.

You need to watch the back pressure as your plumbing on the boat may be more of an issue than the A/C unit. Most boats are nominally 35 pounds on the standard hoses and clamps. If you turn the water on slow you'll get a feel and of course you need to watch for leaks in the lines. You should not need full blast to flush it. If it flushes easily then the pressure won't build up at all.

When mine was really bad I had to flush it for an hour. It then worked well for a while but eventually it got bad again. The real problem was the through hull and that was replaced and relocated to make a shorter run. I would have been better off to have done that right away. Making a new through hull is not that hard and a short run is a whole lot easier to maintain.

[H/V Vega]

Looks like your well covered with good advice but here is one for everyone to note. In tropical high growth areas not only the usual skuz will grow in your hoses but also full blown shell type ani-mules. I have pulled out hoses so clogged with shells and barnacles that they were too stiff to bend. Blowing them out works for a while but in bad cases all you can do is pull out the hose and either run something through it to clear out the crude or put in a new hose. Funny thing is the stuff always seems to grow where you cannot easily see it from the ends so beware of just having a look or trusting the strainer. Intakes are worse than outlets bye the way.

[macdaddy]

Originally Posted by mrfordsr

I have a 2001 50' Gibson with two separate cruisair a/c units. The cooling water outflow on one has decreased to about 60% of the other one. The unit with the lower flow runs briefly and cycles off, shows a "high pressure" message on the control panel, cycles two more times with the same message and then shuts down. I have cleaned the strainer. That did not improve the outflow. Do I have an impeller problem? If so, can I replace the impeller or should I order a replacement pump? I am a novice large boat owner. I would appreciate any advice. This is my first post.

Remove pick-up hose, start unit, when water is pumping, shut unit off, re-attach hose and restrat unit.

Mac daddy
Virginia Beach