Rv 101 - Winterizing Your RV


RV 101: Winterizing Your RV

When RV owners hear the word “winterize” it conjures up thoughts of protecting the RV plumbing system from freezing temperatures. The definition for “winterize” is to prepare something, like a house or automobile, to withstand cold winter conditions. This is interesting because RVs are both a house and a vehicle. So, in addition to winterizing the RV plumbing system we need to be concerned about preparing the RV’s interior, exterior, and chassis components for the harsh winter months too.

With that said the most logical place to start is to protect the RV plumbing system from damage, since this is the number one problem RV owner’s face during periods of freezing temperatures. If you don’t protect the RV plumbing system any water remaining in the water lines or tanks can freeze, expand and break fittings and lines. This can be a very costly mistake next spring!

When I explain how to winterize the RV plumbing system my goal is to make it as simple as possible, and 100% foolproof against any damage caused by freezing temperatures.

The result is my 7-step process to winterize the RV plumbing system:

Before you get started there are a few items you will need. These items can be found in most RV parts stores:

  • Non-toxic RV/Marine antifreeze. The amount depends on the layout and length of your plumbing lines. Two to three gallons will usually do it.
  • A water heater by-pass kit, if one is not already installed on the water heater.
  • A tank cleaning wand to clean and flush the black water holding tank if the RV does not have a built-in tank flushing system.
  • A water pump converter kit, or tubing to connect to the inlet side of the water pump.
  • Basic hand tools to remove and install drain plugs.

Note: Always read your RV owner’s manual for unit specific winterizing guidelines. Some RVs come equipped with built-in winterizing controls.

Follow the steps below that apply to your RV:

Step # 1: If there are any inline water filters remove them. If you have an inline filter at a sink faucet there should be a bypass hose you can install when the filter is removed. Locate and drain the fresh water holding tank. Drain and flush the gray and black water holding tanks at an approved RV dump station. If the RV doesn’t have a built-in tank flushing system you can flush and clean the black water holding tank with a tank flushing wand while you are at the dump station. Drain the water heater tank.

Caution: Never drain the water heater tank when it is hot or under pressure. With no water connected to the RV and the 12-volt water pump in the “off” position open a hot water faucet to remove any pressure on the system. Allow the water heater tank some time to cool before draining. Remove the drain plug or anode rod. You can open the pressure relief valve located at the top of the water heater to assist in draining the tank faster.

Step # 2: Open all the hot and cold water faucets and flush the toilet to help get remaining water out of the plumbing lines. Don’t forget the outside shower if equipped. Locate and open the low point water drain lines by removing the drain plugs. There is one for both the cold and hot water lines. You can use the 12-volt water pump to help force most of the remaining water out of the system, but turn the pump off as soon as the system is drained to prevent damage to the pump. Recap all drains and close all faucets.

Step # 3: By-pass the water heater. The majority of RVs come equipped with a water heater bypass kit. If your RV does not have a bypass kit installed the water heater tank will fill with RV antifreeze before it goes through the water lines, wasting six or ten gallons of RV antifreeze. You can install a bypass kit or have one installed by a local RV service facility.

Step # 4: Install a water pump converter kit to introduce the RV antifreeze into the water system. Another option is to disconnect the inlet side of the water pump (the line coming from the fresh water holding tank) and connect a section of tubing from the water pump inlet into a one gallon jug of RV/Marine antifreeze.

Step # 5: Turn the 12-volt water pump on. It will pressurize the system and start pumping the RV antifreeze throughout the water system. Start at the water faucet closest to the 12-volt water pump and slowly open each valve until the pink colored RV antifreeze appears. Replace the antifreeze container as required. Repeat this process on all faucets from the closest to the farthest away. Don’t forget the outside shower if equipped.

Step # 6: Flush the toilet until antifreeze appears. Pour a cupful of antifreeze down each drain. Pour some RV antifreeze in the toilet and flush it into the holding tank to prevent any remaining water in the tank from freezing. If your water heater is equipped with an electric heating element turn the switch off. This will protect the element if the RV is plugged in while in storage. Make sure all faucets are closed.

Step # 7: Consult your RV owner’s manual for specific winterizing instructions for icemakers and washing machines.

Your RV plumbing system is winterized, but as I mentioned earlier don’t forget to prepare other items on the RV for cold weather storage too. Now you won’t have any unpleasant, not to mention costly surprises waiting for you next spring when it’s time to go camping in the RV.

Happy Camping,

Mark J. Polk


RV Education 101

Mark Polk & Dawn Polk

Mark Polk and his wife Dawn created RV Education 101, a video production and RV information company. Since 1999, RV Education 101 has helped educate millions of RV owners and RV enthusiasts on how to properly and safely use and maintain their RVs. Mark’s favorite past times are RVing in their 35-foot Type A motorhome with their two dogs Gracie and Roxie, and restoring vintage RVs, classic cars and trucks. For more information on using, enjoying and maintaining your RV, visit RV Education 101.