Freshwater Watertank Question

Torcan · Post by **Torcan** » Mon Oct 17, 2011 4:52 pm

I have a 1980 F-25
My watertank sits in the aft starboard side under the captains seat. That is where the cap on the floor is, remove that, then the tank is below with another screw in cap. I am guessing about 15 gallons,(not quite sure)

Question: For winter storage, (Im in Toronto, Canada), do you guys drain this tank? And if you do, do you just syphon it out or is there a drain plug for it?

Thanks in advance.

Scorpyon · Post by **Scorpyon** » Mon Oct 17, 2011 6:08 pm

I live in Sarnia and I disconnected the water lines from the bottom of both my water heater and my fresh water tank, let them drain into the bilge and out the bilge drain. After I finished that I took my air compressor, open my faucets in the head and kitchenette, disconnected the water pump and blew them out with the air compressor. The marina here suggested it, as well as my owners manual. I own an F25 so I imagine yours is the same, my fresh water tank is on the port side however, under the passenger seat. Funny we both own F25's and the layout is different(must be the difference in age...mines a '73), my toilets holding tank is under the drivers seat?

Hope this helps.

randyp · Post by **randyp** » Mon Oct 17, 2011 6:10 pm

I replaced the original metal tank with poly about 12 years ago. When I did that I ran an inlet to a new deck fill mounted on the deck just outside the port side of the cabin (next to the gas fill). The new tank holds 20 gallons. The original was under the port side (opposite from the captains chair side). Then as now I drain the tank via my water pump and then fill partially with water system antifreeze and pump this through the system. That should do it for the winter. In the spring I pump out the antifreeze by filling and refilling the water tank a couple of times to get rid of any residual antifreeze in the system.

Torcan · Post by **Torcan** » Mon Oct 17, 2011 6:26 pm

Scorpyon wrote:I live in Sarnia and I disconnected the water lines from the bottom of both my water heater and my fresh water tank, let them drain into the bilge and out the bilge drain. After I finished that I took my air compressor, open my faucets in the head and kitchenette, disconnected the water pump and blew them out with the air compressor. The marina here suggested it, as well as my owners manual. I own an F25 so I imagine yours is the same, my fresh water tank is on the port side however, under the passenger seat. Funny we both own F25's and the layout is different(must be the difference in age...mines a '73), my toilets holding tank is under the drivers seat?

Hope this helps.

Mine seems to be set up the exact opposite to yours, my toilet holding is under the passenger seat.
I also don't believe I have a water pump? Or do I ? , My "faucets" are just the manual suction pumping type. Kitchenette has just a small "faucet" that you have to pump to get the water flowing, no on or off just pump away.

Thanks for the info though, will look for a drain plug on the bottom of the tank and let it drain into the bilge and out the plug at the back when it gets hauled out in 1 1/2 weeks

thanks for the response also randyp

Scorpyon · Post by **Scorpyon** » Mon Oct 17, 2011 6:37 pm

PO must have changed out the water system then. Either way, u can always disconnect the lines at your 'faucets' and let them drain into the bilge and out the bilge drain plug. My water heater and fresh water tank dont have drain plugs either, i just disconnect the lines from them and let it drain into the bilge, then connect my compressor to the lines themselves. You could use an antifreeze in the lines i guess, I choose not too, simply because i dont want to have to flush them in the spring as many times as would be neccessary.(I also fear an 'after taste' or residue. Just my opinion)

Either way, as long as your lines are mostly clear(90%), you should be ok over winter. Water tends to expand in the direction of least resistance when freezing. If your lines are like mine, they are rubber and have some give if a little water remained(a little, not a whole line!) My concern for water(aside from draining and blowing through), is in making sure the engine is clear of water. A cracked block would suck big time.

captainmaniac · Post by **captainmaniac** » Mon Oct 17, 2011 7:14 pm

I used to do what randyp says but stopped that a few years back. Found I could never fully get the remnants of the antifreeze out of the tank (smell or taste were off, and the water was fizzy forever). Plus I would use a LOT of antifreeze because I had a hot/cold system. The hot water tank would have to fill up before I would get antifreeze out of the hot side. I would use 10+ gallons.

Now I basically run the system dry (opening the faucets), disconnect hoses at the tank and between the pump and rest of the system, and use an air compressor to blow out hot and cold lines through all faucets / head and hot water heater. I changed the plumbing of the hot water heater a bit to facilitate as it had a checkvalve in the incoming cold water line - now I have a T with valve between the checkvalve and tank to either flow fresh water through the checkvalve and into the tank, or allow the tank to drain to the bilge.

Don't forget your head as well. These days that's the only thing I actually put the plumbing antifreeze through. I have the original recirculating setup with an additional holding tank, so process will probably be different for you.

Oh yeah - engines, genny and A/C are done by the marina (that makes it pretty cut and dry who pays if there any freeze-up damage).

Paul · Post by **Paul** » Mon Oct 17, 2011 8:25 pm

I use plumbing antifreeze in my water system however I use a bypass to avoid having to fill the hot water tank. Then in the spring I flush the water tank with a disinfectant cleaner for water systems.

TC · Post by TC » Mon Oct 17, 2011 8:59 pm

I pump the f/w tank empty then disconnect the inlet line at the pump and attach a short hose to a jug of anti. I then disconnect the cold line into the hot water heater and plug it. With one cold tap open at a time a short cycle of the pump forces the water through the lines with antifreeze. I then drain the water heater and one at a time open the hot water taps and they drain back to the heater. I use a rubber hose attacment at each hot water and dribble a little anti back to the heater to make sure. Last I empty the remains of a jug into the f/w tank.
Come spring I use the pump to blow out the anti with water. With minimal in the heater and tank I find I have no odor. The trick come spring is put 1 gallon of water in the tank and pump it through. Do that 2 or 3 times that way you don't mix 40 gallons of water with the 1 gallon of anti in the tank. Also do this before hooking up the heater that way you wouldn't blow anti into the heater and smell it for half the season. I do the whole system, toilet included, using a little less than three 4 litre jugs.

Big D · Post by **Big D** » Mon Oct 17, 2011 10:33 pm

+1 Paul. I blew my system out with air for years until I ruptured a line one winter. Didn't do anything different that I'd done for years but you never really get all the water out with compressed air. Antifreeze from then on. I have a pressurized antifreeze setup that I use to do all boat systems including water, head, engines, genny etc.

I turn the fresh water pump on to empty the tank.
By-pass the hot water heater and drain at the same time.
Pull the water line off the water pump, and attach my antifreeze pressure hose.
Open the antifreese valve, turn on the water pump, and open one tap at a time.
Hook up to dockside water inlet, turn on antifreeze and open closest tap.
Pour a little antifreeze into water heater (the drains are not at the very bottom of most tanks).
Pour about half gallon into water tank.
Come spring drain the bit of antifreeze from tank and heater.
Remove heater by-pass.
Add fresh water tank treatment into tank and turn on all taps. Let sit over night.
Fill tank with fresh water and rinse system.

No funky smells.

trojanmanXS · Post by **trojanmanXS** » Tue Oct 18, 2011 1:03 pm

guess this is where I'm lucky , I dont have to do a thing to my system , previous owner swiped her clean of all holding tanks , lines, toilet,water heater . guess I'll add thsi top favorites in the event I someday have all this stuff and want to figure out howto drain it all. thanks