Winterize Three AC Systems

[theoffice]

I tried using the SeaFlush Adapter on my AC sea strainer and it created air lock. I have three separate AC units that connect to the AC sea strainer. None of the hoses are labeled so I was guessing on which hose works which AC unit. I pinched off two hoses and turned on a single AC unit with the SeaFlush Adapter installed and connected to a five gallon bucket of antifreeze. It consumed about three gallons of AF and flushed. I tried another hose/AC and guessed wrong. I lost power to that AC unit (replace breaker?), which I assume is because I was running the AC unit with the hose pinched off. I tried the third AC unit and its airlocked. I'm thinking of getting a plunger unit to put on the sea strainer thru hull from the outside of the boat on the hard. Then get a pump to push the AF up the thru hull, strainer, pump and through the system until it discharges. I'm thinking I could do this without having to run the AC units and pump. That would get the AC unit done that I need to fix. It would make it safer/easier going forward. I was thinking I could use the same plunger system with the engines and generator flush. Any thoughts or feedback would be appreciated.

 

[ranger58sb]

We can just use a transfer pump* to push AF through the AC water pump and then on to each system. Injection point can be a Trac replacement lid for the Groco sea strainers, or we also have Groco SSC systems in line for flushing too. No need to have the AC pump running.

*Ours happens to be a Milwuakee M18.

Our system isn't perfect for our indoor systems, since one of our AC lines (after the pump) is significantly longer than the other three and because we have common collective discharges... but it stillworks well enough... Would be even better if you have independent discharge thru-hulls, one for each AC system, so you can better monitor thru-put.

-Chris

 

[theoffice]

We have one AC that discharges on starboard side and two AC that both discharge on the same port side outlet. I hooked the plunger up to a 13 gpm fuel discharge pump and set it on the AC through hull. It never created a seal and just spewed antifreeze at the plunger. I hooked the pump to the outlet side of the AC pump hose and it pushed the antifreeze through the system with two hoses punched off at a time. Bottom line: the plunger failed. But the pump worked and now I just need a three way and shut off valve at the outlet side of the AC pump to make it easier next year. Tanks for the advice.

 

[Comodave]

I don’t use the A/C pump to push antifreeze but I have a small 12 volt pump that has garden hose fittings on it. I made a manifold on the A/Cs with a female garden hose fitting. So I hook the pump up to the manifold and put the suction side of the pump in a 5 gallon bucket. Then activate the pump and select the proper hose to pump antifreeze through. Makes it simple and takes about 10 minutes to do both A/Cs and the A/C pump.

 

[theoffice]

Is your connection before the AC pump? So that you push antifreeze through the AC pump then on to the split to each AC? Trying to figure out if it would push through the AC pump.

 

[Comodave]

The manifold is after the A/C pump and before the units. I pump 3 ways with 2 units. I pump back through the A/C pump and out the bottom of the boat. And then through each unit one at a time. It worked very well and was quick and easy. The manifold has a female garden hose fitting with its own shutoff to isolate it when the units are in service. I hook the pump to the garden hose fitting and open the shutoff. Then open the other 3 valves one at a time. We test the output antifreeze with a Refractometer to ensure that the antifreeze is actually strong enough to not freeze. I keep going until it tests -20F.

 

[Cigatoo]

I tried using the SeaFlush Adapter on my AC sea strainer and it created air lock. I have three separate AC units that connect to the AC sea strainer. None of the hoses are labeled so I was guessing on which hose works which AC unit. I pinched off two hoses and turned on a single AC unit with the SeaFlush Adapter installed and connected to a five gallon bucket of antifreeze. It consumed about three gallons of AF and flushed. I tried another hose/AC and guessed wrong. I lost power to that AC unit (replace breaker?), which I assume is because I was running the AC unit with the hose pinched off. I tried the third AC unit and its airlocked. I'm thinking of getting a plunger unit to put on the sea strainer thru hull from the outside of the boat on the hard. Then get a pump to push the AF up the thru hull, strainer, pump and through the system until it discharges. I'm thinking I could do this without having to run the AC units and pump. That would get the AC unit done that I need to fix. It would make it safer/easier going forward. I was thinking I could use the same plunger system with the engines and generator flush. Any thoughts or feedback would be appreciated.

You should be able to blow the ac and fridge water lines (If you have them) out with a shop vac. (Much easier than trying to prime an ac pump)
First Make sure your seacock is open, Set the vacuum so it is blowing and not sucking, put the vac hose on the ac outlet thru hull (usually on the side of the hull) and blow the water back through the lines. Water should be coming out of the inlet thru hull underneath. Do this a couple of times until you are just getting air. Open up the strainer and suck any remaining water water out and you are done. Less than 10 minutes and no messy antifreeze.

 

[theoffice]

You should be able to blow the ac and fridge water lines (If you have them) out with a shop vac. (Much easier than trying to prime an ac pump)
First Make sure your seacock is open, Set the vacuum so it is blowing and not sucking, put the vac hose on the ac outlet thru hull (usually on the side of the hull) and blow the water back through the lines. Water should be coming out of the inlet thru hull underneath. Do this a couple of times until you are just getting air. Open up the strainer and suck any remaining water water out and you are done. Less than 10 minutes and no messy antifreeze.

Thanks for the reply. I was able to use the sea flush funnel hooked to a shop vac to blow out the water. My boats in finger lakes NY so I still mess with antifreeze out of caution for any residual water. It also has three units with one aft, one mid, one forward, separated by 40 feet and lots of opportunity for dips in the line etc. The sea flush with shop vac to blow out most of the water worked nicely though.

 

[Capt Ray]

+1 Shop Vac to suck or blow lines clear on fresh water supply AND drain lines + A/C systems.

A/C seawater pumps are NOT generally positive displacement pumps, which means you can push or suck past their impellers with the shop vac.

 

[Cartouche]

I tried using the SeaFlush Adapter on my AC sea strainer and it created air lock. I have three separate AC units that connect to the AC sea strainer. None of the hoses are labeled so I was guessing on which hose works which AC unit. I pinched off two hoses and turned on a single AC unit with the SeaFlush Adapter installed and connected to a five gallon bucket of antifreeze. It consumed about three gallons of AF and flushed. I tried another hose/AC and guessed wrong. I lost power to that AC unit (replace breaker?), which I assume is because I was running the AC unit with the hose pinched off. I tried the third AC unit and its airlocked. I'm thinking of getting a plunger unit to put on the sea strainer thru hull from the outside of the boat on the hard. Then get a pump to push the AF up the thru hull, strainer, pump and through the system until it discharges. I'm thinking I could do this without having to run the AC units and pump. That would get the AC unit done that I need to fix. It would make it safer/easier going forward. I was thinking I could use the same plunger system with the engines and generator flush. Any thoughts or feedback would be appreciated.

AC Units drain back to the strainer which is the lowest point, no need to try and force anti freeze into unit as it will just drain back out when you stop. had our Mainship up in Canada for 5 years 40 below some winters never had a problem