So you’ve read our 3 part series on winterizing your boats engine and sterndrive. Now it’s time to winterize your boats fresh water system.
There are a multitude of designs and setups for boat fresh water systems so inspect yours and make sure you know how water or in this case antifreeze will flow through your system.
Most boats have a freshwater tank, hot water heater and various faucets and outlets for the water to flow from. You may have a freshwater flush head or a raw (seawater) flush head. It’s important to know exactly how your system is set up. Almost all vacuflush systems use fresh water to flush and will need to be winterized according to the manufactures instructions.
I always start by going to the pumpout dock and pumping the head holding tank. Next I empty the freshwater holding tank by opening the faucets and running the freshwater pump until all of the water is out of the system. Remember to open and drain seldom used things like transom shower heads and washdown hoses. Locate your hot water heater and open the drain and blow off valve on the hot water heater. Make sure you have turned the breaker off for the hot water heater. Once the water has drained from the heater close the drain and blow off valve. Opening the blow off valve will let the hot water heater drain faster.
If you have an on board ice maker follow the manufactures instructions on how to winterize it. I typically turn the water off to the ice maker and let it run until it uses all the water in the line to make ice. Once it stops making ice I disconnect the water line at the solenoid and drain any remaining water from the line. Most ice makers can be damaged by blowing air through the lines or using antifreeze.
Now that your water system is empty there are a few different ways to winterize the system. I have a bypass valve and hose installed on my hot water heater so after I drain the hot water heater I can bypass it and not have to waste 12 gallons of antifreeze filling it up. This is a good hot water tank bypass kit. So with the hot water heater bypassed pour five or six gallons of antifreeze into your water tank and turn on your freshwater pump. Go to the furthest faucet from the holding tank and one at a time turn on the valves until antifreeze comes out of the faucet. Now go to every other faucet and repeat the process.
If your boat doesn’t have or you don’t use your fresh water tank you can winterize by using your 5 gallon bucket you made following this post and a utility pump. Fill the bucket with antifreeze attach the utility pump to the hose bib on the bucket and attach the discharge side of the pump to the dockside water connection on your boat. Turn the pump on and follow the same directions as above to pump antifreeze through your boats fresh water system.
If you have a freshwater flush head, flush the head for enough time to be certain the antifreeze has filled the intake and discharge hoses along with the head pump.
If you have a raw water flush head locate the through hull for the water intake, shut it off and pour one gallon of antifreeze into the head and flush it until it is all gone. Disconnect the hose from the through hull and drain it before reconnecting it to the through hull. Check your hose clamps and replace if needed.
Some boat owners like to winterize the water system by using compressed air to blow it out. I don’t like this method because it can damage faucets and other parts of the system and it may leave a pocket of water in a low laying hose or pipe. By using antifreeze you are insuring the water has been replaced with the proper antifreeze.