How-To De-Winterize your RV

April 02, 2014 -- Mark Polk

When we winterize our RV, we prepare it to withstand cold winter conditions. The term “winterizing” conjures up thoughts of protecting the RV plumbing system from freezing; but “winterizing” also deals with preparing the RV’s interior, exterior and chassis from damage by cold winter conditions. So, it is safe to say when we “de-winterize” our RV, we essentially reverse the steps and prepare the RV for another great camping season.

With that said, let’s concentrate on some of the most important steps in de-winterizing your RV and preparing it for another camping season.


There are two main tasks for a RV water system that has been winterized and stored for a period of time:

1)      Remove RV antifreeze from the plumbing system.

2)      Sanitize the RV water system so it is safe to use.

Remove RV antifreeze from the plumbing system:

If you used non-toxic RV antifreeze to protect the water system from freezing, you need to run fresh potable water through the entire plumbing system until all traces of the RV antifreeze is removed.

Note: If non-toxic RV antifreeze was added directly to the fresh water holding tank when the unit was winterized, the first step is to drain any remnants of antifreeze from the tank.  Next, add potable water to the fresh water holding tank, turn the water pump on and open all of the water faucets. When you see clear water running through the system, turn off the pump and close the faucets.

Make sure you run fresh water through the entire plumbing system to include the outside shower, toilet, ice maker and washing machine, if applicable. Take the water heater out of the “by-pass” mode, if applicable. If the water heater wasn’t bypassed, the antifreeze needs to be drained from the water heater tank and collected in a bucket or other container. With all traces of RV antifreeze removed, you can reinstall any water filter cartridges that were removed for winter storage. The antifreeze that was in the plumbing system is now in the gray and black water holding tanks and will need to be emptied when you have access to a suitable waste disposal site.

Sanitize the RV water system so it is safe to use:

Make sure all of the drains are closed and drain plugs are installed. Take a quarter-cup of household bleach for every fifteen gallons of water your fresh water tank holds. Mix the bleach with water into a one-gallon container and pour it into the fresh water holding tank.

Note: If your RV does not have a fresh water fill location, you can pour the bleach solution directly into a potable RV drinking hose that is connected to the RV prior to connecting the other end of the hose to a potable water supply. Fill the fresh water holding tank completely full of water. Turn on the water pump and run water through all hot and cold faucets until you smell the bleach. Close the faucets and let the solution sit in the water tank and water lines for twelve hours. Drain all of the water and re-fill the tank with potable water. Turn the water pump on and open all faucets, running the water until you no longer smell any bleach. It may be necessary to repeat this process to eliminate all signs of bleach.


Battery condition is dependent on how well the batteries were cared for during winter storage. When batteries are in storage, they lose a percentage of current through internal leakage. A battery can discharge up to 10% a month when it is in storage. If you checked and recharged the batteries while in storage, they should be ready to go. If not, the first step is to fully charge the batteries. Water should only be added to lead acid batteries after fully charging the battery unless the water level is already below the plates. The plates need to be covered at all times. After the battery is fully charged, check and add distilled water as required. If the batteries were removed for storage, reinstall them making absolutely sure they are connected properly.

Caution: If you are not comfortable working on or around batteries, have the maintenance done by an authorized RV repair facility.


Start by opening the LP gas valve at the cylinders or tank and checking the operation of all LP gas fired appliances. Make sure the water heater tank is full of water before testing the water heater. If an LP gas appliance is not operating properly, have it inspected by an authorized RV service facility.  

Note: The LP gas system should have a leak test and gas operating pressure test performed annually. These tests should be performed by an authorized RV repair facility.

After the LP gas appliances are checked, plug the unit into electricity and test all 120-volt appliances and accessories for proper operation. Make sure you have an adequate electrical source (30-50 amps depending on your unit) before testing items like the microwave and roof air conditioner(s).


Just like the battery loses a percentage of its charge in storage, tires lose a percentage of air pressure in storage. Your tires can lose 2-3 psi a month while sitting in storage. Check the tire pressure using a quality tire inflation gauge and adjust the inflation pressure to the manufacturer’s recommendation based on the load. 

Note: Tire manufacturers publish load and inflation tables for proper inflation pressure.


If you have a motorized RV, check all vehicle fluid levels. Consult your vehicle owner’s manual for proper levels. If a fluid level is low, try to determine why and correct the problem. Start the engine and check for proper readings on all gauges.

If you have an onboard generator, check the oil level and service the generator according to specified intervals found in the owner’s manual. Inspect the generator exhaust system for any damage prior to starting. Never run a generator with a damaged exhaust system. If you didn’t use a fuel stabilizer in the fuel system and the generator won’t start, or it continues to surge after starting, have it checked out and repaired by an authorized RV service facility.


Re-install any dry-cell batteries or fuses that were removed from safety devices for storage. If batteries were not removed from safety devices during storage it’s a good idea to replace the batteries now. Test the operation of the carbon monoxide detector, LP gas leak detector and smoke alarm. Inspect all fire extinguishers to make sure they are serviceable and fully charged. Recharge or replace fire extinguishers as required.

As I mentioned earlier, there are many other checks that can be performed in conjunction with de-winterizing your RV, like inspecting seams and sealants for leaks and cleaning the interior and exterior of the RV, but these are some of the checks that I consider most essential.

Happy RV Learning and have a great 2014 camping season!

Mark Polk

RV expert Mark Polk owns RV Education 101 , a North Carolina-based company that produces and sells educational videos, DVDs and E-books on how to use RVs. Mark has more than 30 years of experience in RV maintenance. He retired from the U.S. Army in 1996 as a Chief Warrant Officer Three, specializing in wheeled and track vehicle fleet maintenance operations. He and his wife, Dawn, started RV Education 101 in 1999.

Mark Polk