No it won't, not enough suction. It needs the pressure through the spigot to get it primed.
Printable View
You need to close the valve, mine sucks the antifreeze from the bucket from underneath the exhaust thru 20ft of hose.
If you don't close the valve or have one then you gotta do gravity feed.
https://photos.app.goo.gl/VDTTJ8jmxr3659xd9
I'm talking about using a fake a lake, not a flush kit. Using the fake a lake, there is not enough suction to siphon through the hose unless the hose is already full - hence the need to set the bucket on the swim step and use a spigot. No buckets of coolant inside the boat, either.
Does the thermostat doing anything in a closed cooling system (half system) as far as winterizing? The thermostat controls the antifreeze/ water mixture(50% each) which is in a closed loop.You need to test the mixture for proper freezing point but that should be all? The antifreeze you are adding to the engine eliminates water from the heat exchanger and exhaust manifold and replaces it with the antifreeze. I am still trying to figure this all out myself.
You don't need to use antifreeze with the closed cooling system. You just need to drain the water from the heat exchanger system. It's pretty simple now, just 3 twist plugs to remove and 1 hose connector. Don't even have to do anything for the heater either.