winterize seacocks &/or holding tank?

[wumhenry]

The manual for the Raritan manual toilet in my boat (Bristol 29.9) says something to the effect that seacocks and holding tanks should be winterized. How do y'all go about winterizing holding tanks and/or seacocks?

[US27inKS]

I just did mine yesterday. I followed someone's advice at the club, so I'm not going to say I did it right.

Close the seacock and disconnect the hose allowing all the water to drain out. Empty the holding tank, then pour about a gallon of the pink stuff down the head and flush it into the tank. Reconnect the hose to the seacock.

On my boat I was lucky in that the shower drain and the head inlet use the same through hull. I just turned the shower sump pump on and let it blow the water out of the hose, then turned off the seacock. Then I poured a little pink antifreeze into the shower drain and let the pump push it to the head.

[Valiente]

I have the seawater inlet and the sink drain plumbed into the same vertical, with a T to the head. The T is slightly below the waterline.

To drain the sink, I open the seacock, close the T-fitting to the head, and pull the sink plug. Bye-bye...

To winterize (I haul out, but this would work in the water as well), I close the seacock, open the T-fitting, pour pink stuff in the sink, and pump the head (the holding tank has been pumped out at this point.) The sink is higher than the head, and WANTS to fill the head with every stroke.

After I'm convinced the hoses have pink stuff all the way to the holding tank, I pour a cup into the bowl itself, splash a cup or two into the bilges (in case water gets aboard by some fashion and then freezes...) and that part is done.

[k1vsk]

Some heads are different but typically, the proper way to do this is to remove the seacock hose and insert it into the antifreeze of choice so as to pump antifreeze through the intake hose, head and to the tank. Some toilets hold water around the ring for flush water which will freeze (obviously) if not displaced by antifreeze. Although some people get away with simply pumping on the dry mode to void all water, this isn't a comforting as knowing it's done right.

[wumhenry]

thanks guys.
What about "winterizing" seacocks, if the boat is left in the water? (FWIW, the water is brackish where my boat is moored, in the mid-Chesapeake area.) Would that involve unscrewing the drain plugs to let out trapped water? I did that last year and lost a drain plug, which slipped out of my fingers when I unscrewed it and rolled into an inaccessible crevice.

[sailingdog]

The drain plugs should have lanyards on them.. makes dropping them simple to fix.