Winterizing the AC

[evenkeel41]

Sorry to start talking about winterizing already, but I'm going to anyway.

I have one condenser/water pump for two (Cruisaire AC) units. One unit cools the main salon and the other unit cools the aft cabin and V-birth.

Last year (my first time winterizing this boat) I took the inlet hose off the sea strainer (for the AC) and poured anti-freese in it and let the pump, pump it though the system until it come out the thru-hull. I thought great, that's done...next. How wrong I was. This past Spring I fired up the AC unit and heard water spraying in the engine compartment...again I thought great, but with a very different feeling. The copper line going to the aft cabin unit had burst and was spraying water all over the bildge.

Now to my question...How do I make sure that I'm getting anti-freese to thet back AC unit?

[UNIQUE_NAME]

i have the 1 pump cools both setup also. either on the pump or somewhere in the line is a "Y" fitting, 1 hose for each compressor. i remove each line and run compressed air thru, reconnect and then run anti-freeze thru from the pump. if you don't have compressed air you could use a drill attachment to force the anti-freeze thru each leg. the problem with just using the pump inlet hose as you did, is just because antifreeze comes out the side doesn't mean you have completely flooded BOTH legs. you would be surprised how much antifreeze all the hoses and coils hold.

[jim rosenthal]

I winterize the AC using the following procedure: I get a 5gal bucket and a funnel. I shut the AC seacock and unhook the seawater pump inlet hose. The funnel goes in the hose (I usually use an extension hose as well). Start the pump (turn AC control to "start"). You will have to pour the liquid into the funnel and hold it up far enough to forcibly prime the pump- these pumps are generally not self-priming and will only operate with a flooded inlet. I usually flush 5gals of tap water through the system. Then 5gals of the pink stuff. You know you are done when it comes out of the exit through-hull on the side of the boat. I then hook the hose back up. Don't forget to drain the strainer, and to open the seavalve AFTER the boat is hauled out so that it drains completely. Seacocks should be left open when the boat is hauled so that water is not trapped inside the ball!!! You then close them before the boat is launched, and (cautiously) open them again when you are ready to recommission all the systems.
Several experiences trying to push water out with compressed air have taught me, the hard way, that all the water is NEVER out of the system. NEVER. The system has to be winterized with nontoxic antifreeze for you to be safe. Otherwise the water WILL collect in the low spots and it WILL burst the pipes.