Cruisair help

[HahnR]

Working on the master stateroom A/C - 12,000 btu. The unit hasn't been cooling as well lately, so I set about to do the annual adding of a small amount of R-22. At this time, it's only cooling the air 17 deg. According to the charging curves in the installation & operation guide, I should be seeing around 62 psi on the suction and 175 psi on the discharge with the air & water temps we have. Seeing 58-59 on the suction and 230 on the discharge, superheat is between 11 and 12 deg, and the subcool 10-11 deg. Temps are cooling down here, 74 deg inside air temp and 67 deg water temp so I can understand the lower superheat numbers, but why am I running such a high head pressure? Restriction in the line? The air handler is clean. When put into heat mode, it blows some warm air for a short time until the compressor kicks off. The high side line, which should now be the suction when reversing is way too hot to touch. After running 20 -30 minutes cooling, the compressor starts to ice up. The air handler is not icing up. I haven't measured pressures when heating yet.

Does anyone have any ideas what I should look for?

Randy

 

[doc g]

Not getting rid of the heat. Clean the condenser.....Pat

 

[doc g]

And in heat mode not picking up heat from the water

 

[doc g]

Sorry about multiple posts but can’t edit from iPhone , so water flow could be issue also or dirty condenser / heat exchanger.Check water flow and strainer first.

 

[HahnR]

Thanks Pat. I have not cleaned the condenser since we've had the boat. It's one of 5 units all fed by the same pump, the rest are working fine & good water flow so I didn't think about that. There could be a restriction in that condenser, especially since we went from saltwater to freshwater. I'll rig up the plumbing to backflush the system. Is everyone still recommending phosphoric acid diluted or do I go with barnacle buster?

Randy

 

[doc g]

I used ospho last time but do not remember the dilution . Although I think it was 1 acid to three water.....Pat

 

[HahnR]

Thanks again Pat, I will give that a try

 

[racclarkson@gmail.com]

BB is phosphoric. 1:4 for motors. I’m a bit leery of that in HVAC. I’d go 1:5 or 6.

 

[Pascal]

One of my Two chillers threw a high pressure error yesterday even though i descaled it 6 months ago. The other one was fine so I turn off the valve at the manifold. Pulled the hoses and they were clear. Blowing thru the coil there was something in there that even dockside water pressure would not flush out. I broke the bucket and pump and 4:1 barnacle buster. Descaled for 45 minutes and all good now.

 

[HahnR]

Definitely sounds like that's what I need to do. Robert, I will go with the 1:6 ratio. I'd rather play it safe. I'll let everyone know the results.

Thanks guys,

Randy

 

[IOLANI]

Reading through some old threads as I'm getting ready to flush my CruiseAir cooling lines. I have zero issues right now so it's more preventive maintenance.
Am I correct in assuming it's best to isolate each unit one at a time and pull the exit hose right at the through hull fitting and loop it so as to clean the entirety of the plumbing?
I have two pumps and each one handles two Cruisair units so I'm thinking it may be easier to flush two at a time using a separate transfer pump and a bucket.

Use the Barnacle Buster at 4:1 or 5:1 ?

Thoughts and comments ?

 

[Pascal]

If you want to do a thorough job, it s better to descale everything from the pump all the way to the discharge hose at the sea chest. If access is difficult you can get by with just the coils themselves. Usually shells get stuck at the coil inlet which is the narrowest part of the system as well as at manifolds

There are 2 types of barnacle busters, regular on concentrate. Instructions are on the jugs, I don’t remember off hand

 

[IOLANI]

If you want to do a thorough job, it s better to descale everything from the pump all the way to the discharge hose at the sea chest. If access is difficult you can get by with just the coils themselves. Usually shells get stuck at the coil inlet which is the narrowest part of the system as well as at manifolds

There are 2 types of barnacle busters, regular on concentrate. Instructions are on the jugs, I don’t remember off hand

Thanks Pascal.

 

[omecojh]

I used BB at the recommended ratio, don't remember what it as. Used a 5-gallon bucket in the engine room and ran
into intake hoses. Outlet hoses returned into bucket. Ran for an hour, A/C cooled better.

 

[IOLANI]

If you want to do a thorough job, it s better to descale everything from the pump all the way to the discharge hose at the sea chest. If access is difficult you can get by with just the coils themselves. Usually shells get stuck at the coil inlet which is the narrowest part of the system as well as at manifolds

There are 2 types of barnacle busters, regular on concentrate. Instructions are on the jugs, I don’t remember off hand

Would 4-5 gallons of the proper mix be enough to descale 4 units? Should I plan on devising some kind of filter so the bucket of solution doesn't become fouled with solids to the point that it can't be used on subsequent units? I'm thinking maybe a nylon mesh sock over the end of the return hose like they use on laundry tubs.
Or am I looking at a fresh 5 gallon mix for each unit ? (I suppose it depends largely on the degree of crud I'm seeing....)

 

[carolinacoast]

I have always just flushed all 4 units together into a bucket using a washing machine hose from my HF pump to my strainer cap fitting. then pull the discharge hoses to feed back to the bucket. I run BB a little stronger and longer.

 

[IOLANI]

I have always just flushed all 4 units together into a bucket using a washing machine hose from my HF pump to my strainer cap fitting. then pull the discharge hoses to feed back to the bucket. I run BB a little stronger and longer.

You have all 4 units running off of one strainer and one pump ? Mine has two seacocks, two strainers and two pumps.

 

[carolinacoast]

Your setup is probably better. I have 2 pumps and 2 strainers, but have to manifold over to #2strainer and switch over to #2pump. When I lose a pump, I don't lose function. Strainer-can just valve over to clean one.

 

[43DoubleCabin]

Does anybody ever flush freshwater systems?

 

[whoover]

I used to once a year just to get possible mud and slime out. I used diluted muratic acid.

Walt Hoover