I’m in the PNW and use my boat year round. I do winterize the engine in between uses as it only takes a couple minutes. I winterize the freshwater and holding tank and don’t use them at all during the winter. I run a small heater in the cabin, which would probably keep the freshwater and holding tank system from freezing but it’s nice not to worry about it. Give me a call if you’d like to talk about the engine winterization process. I have the Volvo, too. 425-344-1727.
For the engine:
You need about 1-2 gallons of pink (rv/marine) antifreeze. It's really like 1.25 gallons I think. Easiest with two people.
1) Close seacock in front of the engine box! You access it via the access panel between the engine and cabin.
2) Open engine cover
3) Locate the sea strainer. It should be mounted on the panel between your engine and batteries
4) Unscrew the lid on the strainer (might as well clean it if there's any gunk in there). You'll notice it's full of water.
5) If you have another person, have them start the engine and slowly pour antifreeze into the the sea strainer as the water draws out.
6) If you have a hand, have the other person look out over exhaust discharge (starboard side) and tell you when they see solid pink PG antifreeze flowing out.
7) Kill the engine using the engine stop level mounted on the front starboard side of the engine (it should say "stop" with an arrow on it).
8) Replace sea strainer cap and close engine hatch.
For the holding tank:
1) Pump the tank if full
2) Dump about a gallon of antifreeze in the toilet
3) Pump the toilet until you see pink PG antifreeze enter the holding tank.
For freshwater tank:
1) Turn on freshwater pump at helm station
2) turn on sink and drain tank. Turn off sink when empty.
3) Add 1 gallon of pink PG antifreeze through the deck fill.
4) Turn on sink until you see pink PG antifreeze flowing out.
5) Turn off sink, turn off pump at helm station
That's it!
