Winterizing marine air conditioning system

[gordhodgson]

Question #1
This is my first season with my Hunter 450 and I am not quite sure how to winterize the 2 marine air air conditioning units. Should I take the intake hose off and pump plumbing antifreeze through it or is there a better way?

Question #2

As well I have a Little wonder water maker 300 series that I believe is pickled how would I go about winterizing it I am from Ontario and am currently on the hard for the winter

 

[Rich Stidger]

My system

I also have two A/C units in my h40.5. Here is my system-

I have a Groco raw water strainer on my A/C water intake and I have adapted a reducing bushing that screws into the top of the strainer in place of the cap. This reducing bushing is adapted to a garden hose.

I connect a hose from the strainer to a five gallon bucket and let the A/C pull fresh water out of the bucket for about 5-10 minutes. This is to flush all of the salt out of the A/Cs. The thru-hull is closed at this point so that I only pull fresh water from the bucket. A hose replenishes the bucket as needed.

I then mix up a batch of engine-type low-tox antifreeze in the five gallon bucket. I have installed shut-off valves in each of the water lines from the A/C pump to each A/C. This allows me to shut off the water to each branch.

If the prime is lost to the A/C pump, you will need to re-prime with a drill pump. See the second picture.

With my wife watching from the outside at the discharge ports, I run the A/C drawing the antifreeze into the system. I close one of the valves and as soon as my wife sees the antifreeze exit one port, I close that valve and open the other one. When antifreeze flows from the second port, I shut down the A/C. This method uses the least antifreeze and puts as little as possible into the water.

After the boat is hauled, I open the seacocks and let any seawater in them drain. Close the seacocks for the winter.

BTW, I do exactly the same method for my engine and generator.

See pix below.