Sea Ray 4200 Aft Cabin - Forward Cabin A/C

[MARGEEZ]

We are experiencing a LOW level of water flow to the forward cabin A/C, now to the point the a/c will not run. It has been 'de-scaled' (June & will do again 9/26/2014) and water pressure (90) flushed (mud has come out). Salon (mid) and aft cabin are fine. The water flow has been 'pinched' in the attempt to get more water forward. Suggestions?
(our A/C tech threw out the idea of adding a water pump in the forward cabin ...of course during a haul out...not something I have entertained seriously).

 

[ktcanuck]

How was it descaled? I have had two operations done on mine over the last 18 months. First in Atlantic City some folks used Muriatic Acid. They drew 5 gallons through, let it sit for a few minutes , then flushed out. The next time, 4 weeks ago in North Palm Beach, the tech connected hoses to the three outlet hoses (at the through hull) and flushed Barnacle Buster for three hours, reversed the flow and flushed for another hour. I saw a small effect the first time and a huge difference the second time. All three outlets are accessible (strange for this boat!). You might want to try a good flush if you haven't already.

 

[kevin27]

Do not use Muriatic Acid. My A/C guy told me it can damage the metal of the coils and they never use it. Best to use Barnacal Buster or simular as described above.

 

[ktcanuck]

MA attacks the solder joints. A few minutes won't hurt but I am guessing a few minutes won't clean the pipes properly either.

 

[ktcanuck]

MA attacks the solder joints. A few minutes probably won't hurt but I am guessing a few minutes probably won't clean the pipes properly either.

 

[MARGEEZ]

I believe the acid was used.... in June, placed in lines (remained in lines for quite some time) then flushed out with ALOT of barnacles and mud. A/C ran 'well' for about 2 months. When front a/c started again to cycle off, had another a/c tech 'descale' recently with no barnacles/mud, flushed the system with high pressure water (dock water is HIGH PRESSURE...90lbs) and cleaned out the intake line (full of barnacles). Also 'redirected' the water flow to give the front cabin 'the most' flow. Had to re-adjust as then the aft cabin did not get enough flow. The front cabin is no longer working (cycles off within 5 minutes). The Salon has just started to cycle off if aft cabin runs at the same time. 'Talking' about putting in a new line to the front a/c...(or new individual water pump for front...or new larger water pump for the 3....which would take a larger intake ....).

 

[ktcanuck]

Is the flow down on the other two outlets as well? Some places on East Coast FL have a sediment in the water that builds up on the incoming side of the strainer. Needs to be cleaned often. But I guess you checked the strainer first. The forward line has always been weak on my 420AC but does run ok so you shouldn't need to add pumps - just make sure the lines are clear and the strainer is free of debris, sediment and barnacles.

I wonder if your raw water pump is beginning to fail. I recently had to renew mine after similar symptoms. Buy the pump on line rather than through a tech. You can buy it for much less than the tech has to charge.

 

[MARGEEZ]

Is the flow down on the other two outlets as well? Some places on East Coast FL have a sediment in the water that builds up on the incoming side of the strainer. Needs to be cleaned often. But I guess you checked the strainer first. The forward line has always been weak on my 420AC but does run ok so you shouldn't need to add pumps - just make sure the lines are clear and the strainer is free of debris, sediment and barnacles.

I wonder if your raw water pump is beginning to fail. I recently had to renew mine after similar symptoms. Buy the pump on line rather than through a tech. You can buy it for much less than the tech has to charge.

Most probably as the Salon cycled off yesterday (2x) until I turned off the aft cabin (front cabin was off due to cycling off at about 5 min). Have talked re new pump among other things.

 

[bahamabreisus]

Here in NC with warm water during the summer months, I have to clean strainer every 2 or 3 weeks and blow all the water lines out. After cleaning your strainer, disconnect the discharge hose from the pump, buy a fitting from your hardware store and hook your dockside water hose to it, let it run about 30 mins, you will not believe the crap that come out.

 

[MARGEEZ]

We have been cleaning the strainer every week (can not believe what one finds in the strainer!!!). All lines have been flushed (& descaled) from the seacock ..in/out.... After the 1st descaling (June2014) not much more (barnacles) have come out (2nd descaling was within last 6 wks). High pressure water flush had a bit of 'mud' come out. Water lines were 'adjusted' to take water from aft/center to shift to forward. Then the aft cycled off so adjustments made to keep it running. Front cabin still cycles off after 5 min (instead of less than 1 min). Salon (center) cycled off 2x yesterday (19OCT2014) prior to turning off aft a/c. The water pump was replaced (per paperwork) just about 1 yr ago. A/C manufacturer 'Expert' to come take a look...(repair tech is from the manufacturer too!).
Center & Aft overboard flow is great ...Front is just more than the 'trickle' it had been.

 

[bahamabreisus]

Is your pump magnetic drive, if so you might pull the impellor and clean the magnets on the impellor itself and the inside of the housing. They tend to get fouled also. We have a similar set up to yours, and its an ongoing battle in warm weather. I have considered a 2nd pump also for the forward AC. I think the existing thru hull is large enough to handle both pumps. I think our thru hull is 1 1/2" inside. Our center discharge is the one that slows first. If yours is like ours, there is a "T" connection near the side unit, disconnect there and flush thru the front unit.

 

[ktcanuck]

I don't think there's a T in the 420AC system. The three lines come of the manifold independently and run directly to each a/c unit.

When the system was flushed did they take all lines off at the hull and recirculate? For the forward unit it would not be difficult to probe the line from the manifold to the forward unit and then from the forward unit to the hull outlet.

Aside from your tech's time the most expensive part is likely to be the pump and that is a good spare to carry anyway.

 

[MARGEEZ]

A/C is now working after a PROPER cleaning (3rd times a charm)! Front A/C overboard discharge line replaced (completely clogged). Also, re-plumbed aft cabin a/c drain/discharge line from engine room bilge to aft cabin sump (to remove the constant water in the engine bilge---now if there is water in the engine room bilge, there must be a leak from 'somewhere' ...). Why would someone engineer a 'water line' to a bilge instead of a sump?

 

[ktcanuck]

According to my drawings the"engineers" routed it to the aft sump. The production guys had different ideas. Mine is the same as yours was!