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Flush A/C System on 1999 450 Voyager

Discussion in 'Carver Yacht' started by Jim Caperton, Aug 23, 2021.

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  1. Jim Caperton

    Jim Caperton New Member

    Joined:
    Aug 20, 2021
    Messages:
    1
    Location:
    Pensacola, FL
    Good morning all.

    I have a 1999 450 Voyager and have been attempting to flush the raw water lines in the A/C system. No problem with the strainers etc, but still getting "HPF" on two of the four units. Filters are clean and units are serviced. Is there an adapter that I can put on top of the strainer housing that will allow the vacuum needed to draw water into the pump? The location in the bilge is quite tight and not easily accessible for leverage.

    Is there a way to flush the system in a recirculating loop or can I only fill till I see it coming out of the drain, turn it off and let it sit for 20-30 minutes? YouTube is great for general info, but I am hoping to hear from folks with the 450 Voyager and how they do this maintenance.

    I do have lots of water exiting the hull so I do have good flow to two of the units. I guess my next step is to take the water lines from the problem units to ensure that water is getting to and from them at the end as they are the farthest down stream from the pump.

    Many thanks

    JC
  2. bayoubud

    bayoubud Senior Member

    Joined:
    Feb 19, 2017
    Messages:
    1,149
    Location:
    Florida
    You probably have debris built up or blocking the units. It is recommended that you circulate the descaler solution from the input side to the output side using a pump in a bucket which will collect the debris. Google Trac Barnacle Buster, you can see equipment used and directions. There are also diy you-tube videos.
  3. Pascal

    Pascal Senior Member

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    Messages:
    8,119
    Location:
    Miami, FL
    Ad to you first question about drawing vaccum thur the strainer housing, I m not sure I understand what you re trying to accomplish. With the strainer closed and the sea cock open, water should flow up to the pump so it starts right away.

    Unless carver messed up the install and the hose between the strainer and the pump inlet has high points.

    if that s the case you can either reroute the hose correctly or add a valve at the strainer outlet. By closing this valve before opening the strainer you save the water upstream of the strainer to avoid loosing prime. It s just bandaid though.

    The best way to decale your coils is to Circulate barnacle buster (avail on Amazon) diluted 4:1. Easy. Get a 5 gallon bucket and 120v bilge pump. Run a hose from the pump to the coil and then another hose from the coil outlet back to the bucket. Run for at least an hour. You can also buy a pre assembled bucket with lid, pump and hoses as a kit

    depending on your set up you can do multiple AC at one time or daisy chain them.

    also make sure that there is no hard restriction inside the coils, hoses or manifold.

    if you have something blocking a hose or coil, usually at fittings, the low pressure of the bilge pump may not dislodge the debris
  4. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    818
    Location:
    Chesapeake Bay, USA
    The Groco SSC flush adapter can be fitted either to your AC strainer (outlet side), or to the thru hull that feeds that strainer. Former usually seems slightly easier. (Or generally a basic T fitting with a valve on it from anyone can work.)

    Then you can use that fitting to inject a cleaning product (Barnacle Buster, Rydlyme, Acid Magic, etc.) into the system. Generally you'll need to use both an electric transfer pump AND the AC pump to get product into all of your lines. (The AC pump, without transfer pump assistance, may be difficult to prime and then may tend to only push product through the shortest path to discharge.)

    If you can get around to the side of the boat and capture discharge, you can recirculate. Folks often do that when the boat is hauled/blocked, I suspect less so when the boat is still floating.​

    20-30 minutes is maybe inadequate. I think I remember BB directions suggest a couple hours of soak time. Whatever the directions say...

    If that doesn't work... the single outflow from your AC pump is likely routed to a manifold, and you may have to attack it from there. If so, transfer pump, one line at a time.

    Or... you may have to work backwards from each clogged AC system. In that case, disconnect a given hose at the manifold, establish a catch-pan system of some sort, and inject from the AC end. Potentially messy.

    Especially if you have a hard/solid clog in any of the lines.

    FWIW, we just had to work through almost all of this on our new-to-us fixer-upper. I met my match after the first three steps, called a pro, and he used a system of hoses with fittings and a squeeze bulb (as from an outboard motor gas tank, instead of an electric transfer pump). One of the clogged lines cleared relatively quickly, but he had to work from the manifold to do it. The other was a hard clog, as maybe an AC unit that hadn't worked in years. On that one, he had to work from the manifold, then from the AC, then from the manifold, then from the AC... until it finally opened up.

    -Chris
  5. Jnicholas

    Jnicholas Member

    Joined:
    Dec 7, 2013
    Messages:
    94
    Location:
    Long beach ca
    I have 4 ac units on my 450 Voyager. I have no error codes, cooling and heating fine. But units have not been flushed for the 6 years I’ve owned her, and who knows from past owner. I installed a hose connector in line from through hull to ac pump. So I can start unit, turn on fresh water, then close through hull valve and one by one flush each unit with fresh water. Difficult to get to units for return lines so I have not used BB or similar chemicals. Any similar chemical I can apply and just allow to flow overboard?
  6. Pascal

    Pascal Senior Member

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    8,119
    Location:
    Miami, FL
    Not really. You need to circulate the cleaning solution for 30 to 60 minutes. You will have to run a hose back from each unit. The easiest way is to put a bilge pump in a bucket and do it unit by unit.

    flushing with fresh water isn’t going to do much.
  7. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    818
    Location:
    Chesapeake Bay, USA
    Both Barnacle Buster and Rydlyme advertise they're safe for flushing overboard.

    Both also recommend recirculating, but they also have some Plan B instructions for a "fill and soak for a while, repeat" alternative.

    -Chris