Check out the RV heater manufacturer's website as they will give you the proper storage instructions. If the manufacturer's recommendations aren't available, take it easy and remember that storing a heating appliance is not as stressful as this sounds! You'll want to do the following: Allow plenty of cooling time for your unit before storage. Clean all dirt and dust from surfaces with a damp cloth or sponge. Drain the tank by opening the valve at the bottom or side of the unit so water can drain out. If you have a propane RV heater, please make sure there's no gas in it.