Supplies You Will Need
Non-toxic RV antifreeze: Two - Three Gallons
A water heater bypass kit, if not already installed
A wand to clean out holding tanks
A water pump converter kit
Basic hand tools to remove drain plugs
Remove and bypass inline water filters
Drain the fresh water holding tank
Drain and flush the gray and black holding tanks
If your RV doesn't have a built-in flushing system, clean the black tank out with a wand, or use a product like Flush King which allows you to clean both the black and gray tanks.
Drain the water heater
Remove the drain plug and open the pressure relief valve. Caution: never drain the water heater when it is hot or under pressure.
Open all hot and cold faucets
Don't forget the toilet valve and outside shower as well.
Locate and open the low point drain lines
There will be one for the hot and cold water lines. Using the water pump will help force water out, but turn it off as the system is drained.
Recap all drains and close all faucets
Bypass the water heater
If you do not have a bypass kit installed, the water heater will fill up with antifreeze before it goes through the water lines. This would waste close to six gallons of antifreeze.
Install water pump converter kit
OR disconnect the inlet side of the water pump (the line coming from the fresh water holding tank). Connect a piece of clear tubing to the inlet side of the pump and put the other end into a one gallon container of non-toxic RV antifreeze.
Turn the water pump on and pressurize the system
Starting with the closest faucet, slowly open the hot and then cold valves until antifreeze appears. Replace the antifreeze container as required.
Repeat this process on all faucets
Start with the closest and work your way to the farthest faucet. Don't forget the outside shower, if equipped.
Flush the toilet until antifreeze appears
Turn water pump off and open faucet to release pressure
Go outside to the city water inlet. Remove the small screen over the inlet and push in on the valve with a small screwdriver until you see antifreeze. Replace the screen.
Pour a cupful of antifreeze down each drain
Also, pour a couple of cups in the toilet and flush into the holding tanks. If your water heater has an electric heating element, make sure it is turned off. This will protect the element if the unit is plugged in while being stored.
Make sure all faucets are closed
Consult your owners manual
If your RV is equipped with an ice maker and/or washing machine, consult your manual to learn the process for winterizing those units.
