RV Dewinterizing And Sanitizing Basics

The claws of winter are finally retracting, and spring is on its way! The call of adventure and your favorite camping spot is calling your name, and you are itching to answer. Before you hitch up and head out, however, there are a few steps you need to take first. In addition to your regular spring RV maintenance, you will want to dewinterize and sanitize your water system. This process involves flushing out the antifreeze used to winterize your RV, as well as running a sanitizing solution through all of the water lines and faucets.

Taking your RV to a facility to have this done is a bit inconvenient, not to mention expensive. With shop rates around $100 per hour, a job which would cost you an hour and a few bucks DIY style now cuts into your travel budget with a heavy hand. We will help you avoid all of the debacles with this high-level walkthrough. Scroll on faithful reader!

Key Steps

  • Check the weather for freezing temps

  • Flush Antifreeze out of all water lines

  • Place plug in the water heater and turn off water heater bypass valves

  • Prepare sanitizing solution using 1/4 cup of bleach per 15 gallons of water

  • Sanitize pouring bleach solution into holding tank, filling with water, and pumping through all faucets

  • After 12 hours, drain the entire water system and pump fresh water through all lines until no bleach smell remains

  • Install Anode Rod into the water heater and filter cartridge into the internal water filter.

Flush Out Antifreeze

Flushing the antifreeze out of all of the lines involves either pumping water through the water lines to remove the antifreeze or to drain the lines using low point drains. If you used the blow out method to winterize your RV as we mentioned in our RV Winterization post, you can skip all of this and move to the sanitization steps. Before flushing your system, you will want to drain the antifreeze from your fresh water tank if you placed any in it during winterization.

To flush your water system of antifreeze either connect a hose to your city water inlet or use potable water in your fresh water holding tank. We prefer the city water inlet as it makes the sanitization steps easier later on. Once you have your water connected, use the pressurized water from the city inlet or the onboard RV water pump to flush all of the non-toxic antifreeze out of the lines. It will collect in your holding tank until the next time you dump your tank.

Simply run both hot and cold on all faucets until the water runs clear. Don’t forget the toilet and any outdoor kitchen faucets and exterior showers. It doesn’t take long to flush it out, especially if you were able to by-pass the water heater during the winterization steps. If not, you may have six gallons of antifreeze in the water heater.

Quick Tip: Make sure you are using your pressure regulator like you would when camping. 40-50PSI is all the water pressure you need. You can find info on this and other essential items in this post.

Water Heater Set-Up

Moving to the next step, you will want to address your water heater. We don’t mean telling it good morning, more put the plug back in it if needed, and sort out your bypass valves. Ideally, it is nice to have a separate plug for your water heater without the anode rod on it, but it isn’t vital in our experience. 

The Water Heater

As previously mentioned, if you didn’t leave the plug in the water heater during the winter, find said plug. What we like to do is use an old anode rod which we cut off, so it is just a plug. Then we can put in the new rod once the sanitization process is complete. If not an option, just put your thread tape on the threads of the anode rod and slap it in there. No need to get crazy and overtighten it. Just get it good and snug.

Bypass Valves

Additionally, you will want to sort out your water heater bypass valves if your RV is so equipped. These can be found in various locations depending on your RVs manufacturer. Our valves are hiding behind a panel inside the RV below the oven. Also, the typical set-up we have seen uses three valves, though some models may only have one or two. 

In the reverse order of when you winterized it, turn the hot and cold valves to the open position and the bypass valve to the closed position. Referring to the valve images, the valve is open when it is parallel with the water line, and closed when it is perpendicular. At least that is the case with our RV.

Prepare Sanitizing Solution

Your next step is to conduct some basic chemistry and mix bleach with water. Do not try to do this in your Sunday best if you will. Murphy’s law seems to get more prominent the fancier and more expensive your clothes. Don’t fall victim to Murphy, wear clothes you don’t mind getting bleach on. 

Items Needed

Items required for sanitizing make up a short list — household bleach, measuring cup, funnel, and a one-gallon jug or pitcher. You will use the jug or pitcher to mix water with your bleach before pouring it into your holding tank using the funnel. If you don’t have a funnel, you can make one by cutting the side off of a water bottle. 

Also, you may want to entertain the idea of wearing chemical protective gloves and some eye protection. We hear getting bleach in your eye doesn’t exactly tickle. 

Pretty much the universal rule of thumb is to use 1/4 cup of bleach for every 15 gallons of water your fresh water tank holds. For example, our freshwater tank holds 44 gallons, so we eyeballed it at just shy of 3/4 of a cup of bleach. Directly pour the bleach in your jug or pitcher and then fill up the rest of the gallon with water. You are now ready to begin the sanitization process. Or are you?

The Sanitizing Process

As the classic meme states, one does not simply…pour their sanitizing solution in the holding tank without making sure all valves are closed. Provided your fresh water tank is empty or close to, you should make sure all valves are closed both on the fresh water holding tank (should yours have a valve) and low point drains. If you have water in your holding tank, you should drain it as to not throw off the concentration level of your sanitizing solution.

Fill Your Freshwater Tank

And so it begins! Using your funnel, pour your bleach solution into your holding tank, and then using potable water, fill your holding tank. It is important to fill your holding tank so the entire tank gets sanitized. Some folks prefer to fill it half way and then drive it around the block a few times. We like to fill it and let it sit full. 

Sanitize Water Lines

Now that your holding tank is full and ready to go, it is time to run your solution through all of your water lines. To do this, turn on your onboard water pump to pressurize the system and then go to your first faucet. Turn on the cold water and let it run until you can smell bleach. Turn off the cold water and turn on the hot water until you once again smell bleach. The hot water may take a minute as it is filling the water heater. Also, you don’t need your water heater turned on for any of these steps.

You will want to follow this same process with all of your faucets and your shower. Don’t forget about any of the sinks and showers on the exterior of your RV.

Now comes the easy part. Walk away. Just walk away. You need to let the bleach solution sit in the lines for at least 12 hours. We have heard of folks doubling the amount of bleach in their solution and letting it sit for six hours. Up to you of course, though it may be harder to get the bleach flavor out of the lines later if your mix is over concentrated. 

Draining The System

You are on the home stretch now! Your next step is to open your low point drains and holding tank valve if you have one. If you don’t drain the water system, it will take hours and an amazingly large amount of water to get the bleach taste out during the remaining steps. Ain’t nobody got time for that!

As per previous, open all of your drain valves and let all of the bleach water drain out. Your concentration should not be so intense as to kill everything in your neighborhood, which is why it needs to sit in the system for 12 hours. If you are concerned about it though, we suggest researching how to properly dispose of the bleach water in your local area. We don’t pretend to know every law in every state. Or our own for that matter!

As our RV is just a little fella, it drains rather quickly, if you have a monster-sized RV, you may want to grab a Snickers. It’s going to be a minute peeing the water out. 

Refill The Water System

You now want to refill your water tank to be able to flush the bleach smell out of all of the faucets. Follow the same process you used when smelling for bleach. This time, you DON’T want to smell bleach. You may have to repeat this process a couple of times before it is all said and done. Just depends how much bleach taste and smell you can tolerate. 

Your last step is to drain the water heater to install your new anode rod. After that install your new water filter cartridge into your internal water filter (if you have one). Now you are ready for another remarkable season of camping adventures!

Final Thoughts

In closing, we wanted to point out how much money you just saved. First off, a lot of shops will charge you a minimum of an hour labor. There be $100 right there give or take $10 based on shop rates. Not to mention the pain of taking your RV to a shop to have it done and having to go back and retrieve it.

For the most part, this entire process takes two hours tops (ish), and you most likely have everything you need to get it done. We wish you good luck on your DIY RV dewinterizing and sanitizing voyage!