7 Easy Steps to Winterizing Your RV Plumbing System

7 Easy Steps to Winterizing Your RV Plumbing System
October 19, 2016

Protect your RV plumbing system from plummeting temperatures with these seven easy steps from RV expert Mark Polk.

It’s always sad to come to the realization that another camping season is winding down. Depending on where you live, part of this realization is preparing the RV for winter storage so it will be ready to go camping again next spring. A major part of winterizing your RV is to protect the RV water system from potential damage, caused by exposure to freezing temperatures. Frozen and damaged water lines are in fact the most common problem related to not winterizing your RV, or not properly winterizing your RV.

The RV plumbing system is the most vulnerable system to damage caused by plummeting temperatures. The good news is it is easy to protect the RV water system from this potential threat. Here are 7 easy steps to winterize your RV plumbing system.

Items to buy before you get started

  • Non-toxic RV antifreeze: 2 – 3 gallons, depending on the length and layout of your plumbing lines.
  • Water heater by-pass kit, if not already installed.
  • Wand to clean out the black water holding tank if the RV doesn’t have a built-in clean out system.
  • Water pump converter kit, or tubing to connect to the inlet side of the 12 volt water pump.
  • Basic hand tools to remove and install drain plugs.

Note: Be sure to read your owner’s manuals for unit specific winterizing guidelines. Follow the steps below that apply to your RV.

Step # 1: If you have any inline water filters remove and bypass before starting. Drain the fresh water holding tank. Drain and flush the gray and black water holding tanks. If the RV doesn’t have a built in flushing system clean the black tank out with a wand. Drain the water heater. Open the pressure relief valve and remove the drain plug.

CAUTION: Never drain the water heater when hot or under pressure. With no water hooked up to the RV and the water pump off open a hot water faucet to remove any pressure on the system. Allow the tank to cool before draining.

Step # 2: Open all hot and cold faucets; don’t forget the toilet valve and outside shower. Locate and open the low point water drain lines. Use the water pump to help force most of the water out of the system, but turn it off as soon as the system is drained to prevent damaging the pump. Recap all drains and close all faucets.

Step # 3: By-pass the water heater. If you do not have a by-pass kit installed the water heater will fill up with RV antifreeze before it goes through the water lines, wasting six or ten gallons of antifreeze.

Step # 4: Install a water pump converter kit, or disconnect the inlet side of the water pump (the line coming from the fresh water holding tank) and connect tubing from the water pump inlet into a one gallon jug of RV antifreeze.

Step # 5: Turn the water pump on and pressurize the system. Starting with the closest faucet to the pump, slowly open the hot and then cold valves until the pink colored RV antifreeze appears. Replace the antifreeze container as required. Repeat on all faucets from the closest to the farthest away. Don’t forget the outside shower.

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 into the holding tank to prevent any water in the tank from freezing. If your water heater has an electric heating element, turn it off. This will protect the element if the unit is plugged in while in storage. Make sure all faucets are closed.

Step # 7: Consult your owner manuals for winterizing ice makers and washing machines.

The unit is winterized. Now, next spring when it’s time to head out in the RV you won’t have any unpleasant, not to mention costly, surprises waiting for you.

Want to learn more about RV winterization? Check our library of RV articles and videos and stay tuned for more information about best practices when storing your rig.

Mt Rushmore KOA at Palmer Gulch

About the Expert

MarkheadshotKOAKOA’s resident RV expert, Mark Polk, and his wife Dawn started RV Education 101 in 1999. Since that time RV Education 101 has helped educate millions of RV owners and RV enthusiasts on how to properly and safely use and maintain their RV. Mark’s favorite past times are RVing in their 35-foot Type A motorhome, and restoring vintage RVs, classic cars and trucks. For more information on using, enjoying and maintaining your RV visit RV Education 101.


7 Easy Steps to Winterize Your RV Plumbing System

23 Responses

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  1. Harry Westcott

    Excellent advice about winterizing. I’ve found it easier to just pour a gallon of “pink” into the fresh water tank and pump it around. Saves messing with the pump inlet from the fresh water tank.

    October 5, 20114:24 pmReply
    • Karen Hawkins

      Hi Harry

      OK….I’ll bite…….What’s “pink” ???? Pepto Bismo???
      we have a 18′ camping trailer…and live in hot AZ
      so I don’t think we need to do any of this … do we???

      We’re new at this camping thing & only used our trailer
      twice this year so far.

      October 5, 20118:13 pmReply
      • CPT Kirk

        Hi, Karen!

        You posted quite awhile ago so hopefully you received an answer to your question before now. But if not…

        “Pink” is the anti-freeze to put into your RV’s water lines. It is colored pink/red. You’ll want to replace the water in your plumbing lines with anti-freeze if you anticipate the temerature dropping below freezing. If water is left in the lines, and freezes, the resulting expansion of the water turning into ice will crack your lines/fittings. You’ll then have water leaks when you next use your RV.

        You can purge or “blow-out” your water-lines with air, but some residual water may remain in the lines to settle in a low-spot. If that small amout of water freezes you may still crack the line/fitting where the water settled. Hence, it is probably best to use the anti-freeze.

        Camping in freezing temeratures is moe tricky. You need to keep the water lines from freezing! The warm interior of your camper/coach (Woo-Hoo for propane furnaces!) will keep the interior water lines from freezing, however your holding tanks will not be protected unless your camper/coach is constructed to do so (ie, enclosed and heated tanks).

        All said, freezing temperatures and an RV’s water system do not mix well. You must remain ever vigilant to keep the water from freezing whilt the RV is in use, and completely remove the water when th RV is in storage.

        I hope this helps… Happy Kamping!

        January 3, 201210:43 am
    • David Wicks

      Thanks Harry…. I never thought of that….. that will be much easier…. thanks again!!

      October 5, 20118:52 pmReply
    • Bob

      NOt the best way, It can be diluted with any existing water and not have the low end freezing point protection reccomended

      October 6, 20115:31 amReply
  2. Dennis

    I have never used RV Antifreeze in the fresh water system as I was concerned that it was not very safe if any of it was injested. Has that changed in recent years. Usually, I use the RV Antifreeze in the p-traps and holding tanks after draining the fresh water tank and water heater. There always seems to be a residual amount of liquid in the tanks, but just a little. I live in the high desert of California where winter temps dip from 25 to 32 degrees in the early mornings. Should I be more careful?

    October 5, 20115:52 pmReply
    • john lowry

      When I go to use the camper in the spring I flush the system.Then I put a mix of bleach with water & run it through the system.After that I drive around a little.Then let it sit for a while. Then flush the system again.Then put backing soda & water mix in & do the same thing.The baking soda get ride of the smell of bleach.The bleach cleans out the system in many ways.I also put the bleach in during the season to keep the system clean.There is a # on the bleach jug to call.They will give you the right mix per gallon to use.I have done this for the past 30 yrs & never any residual.Also I reuse what is in the fresh water system.I put this down the black tank for the winter & dump a little of that out.I feel this keeps the whole system in check

      October 7, 20118:09 amReply
      • john lowry

        I forgot to say that after dumping the system for the winter.I hook up a compressor to flush out any water left in the system.Then put in the antifreeze

        October 7, 20118:14 am
  3. David Wicks

    Great site…. with lots of good tips…. really helps!! thanks again

    October 5, 20118:55 pmReply
  4. Jimbo

    We were supposed to get a cold snap here last weekend so I winterized ours. I’m thinking about taking it back out this weekend since it warmed back up. Do I need to sanitize the water system if I just use it for showering and washing dishes? I never trust any campground water for drinking so I bring bottled water for our drinking water.

    October 6, 20114:15 pmReply

    In mid January I would look out the window and see 30 degrees below zero F. and I would begin to worry about my holding tanks and whether or not they were fully drained. Now I pour a half gallon of RV anti freeze down the kitchen drain and toilet so that any water in the holding tanks will not freeze.

    Now all I have to worry about is starting the car!!

    October 6, 20116:44 pmReply
  6. Kathy

    What if you are planning on camping at least once a month during the winter, should you still winterize the RV for those in between times?

    October 6, 20117:04 pmReply
    • CPT Kirk

      Hi, Kathy!

      You’ll want to winterize whenever you anticipate the temperature to drop below freezing. You do not want water to freeze in your RV’s plumbimg.

      Happy Kamping!

      January 3, 201210:52 amReply
  7. Kacey

    Great Advice! I live in ND where actual air temp can get to -40F. It is major business for the dealers up here to winterize campers. I will be doing my own this year and should I somehow not get it I would hope to see some tips on detecting and fixing leaky water lines in the fall.

    October 7, 20117:54 amReply
  8. Frank

    I just flush my system then I hook the air compressor and open taps one at a time from closest to furthest and flush toilet to blow any air out of that line as well.When all lines are done I go around again to ensure no water sitting in low spots of the lines and then drain traps and add some RV antifreeze to them.

    October 9, 20118:45 amReply
  9. Ron

    In addition to the great KOA winterizing tips, some of the RV companies, dealers, and individual RVers offer great videos on Youtube.

    December 7, 20116:19 pmReply
  10. CPT Kirk

    And don’t forget the drain traps!

    During non-freezing months, keep your drain plugs in to prevent holding-tank odors from entering the coach when the “water-trap” either evaporates away or is reduced from coach movement while traveling.

    During freezing months, replace the water in the drain trap by pouring some anti-freeze down the drain. Water freezing in the trap can crack your drain pipe.

    Happy Kamping!

    January 3, 201211:01 amReply
  11. Dave the Camper

    RE this part of Step 6: If your hot water heater (HWH) has an electric heating element, turn it off.
    This statement needs to be the first instruction of Step 1! Otherwise your electric heating element will be toast/destroyed when the drain plug is removed OR if the lowpoint drain valve under the trailer is opened. I almost destroyed my heater element when winterizing last November, as I forgot to turn the switch OFF when packing out at our last camping trip.
    Suggestion: Make turning off this switch part of YOUR campsite pack out check list. It’s usually located in the HWH compartment itself. The switch INSIDE the camper labled Water Heater only controls the HWH propane heat source.

    January 18, 20123:45 pmReply
  12. Chad

    I live in Alberta, Canada where -40 degrees F is not uncommon. I have been winterizing my trailer for 6 winters now and have NEVER used any antifreeze in my fresh water system. All I do is drain all of the tanks and water heater as recommended then blow out my lines with an air compressor attached to my “City” water connection. As long as the compressor is regulated to 80 PSI and all of the lines are blown out fully you will not have any problems. I do use 2 gallons of antifreeze but only to pour down my p-traps to keep them from cracking.

    The antifreeze process works as well but I can easily winterize my RV’s plumbing system in 20 minutes or less and have never had a line break. I certainly am not trying to sound like a know-it-all but I must say that I have never understood why some experts still push this time consuming, more complicated and more costly antifreeze system.

    March 6, 20128:45 pmReply
  13. Sonny Bagueros

    How important is it to drain the low point water drains? I know Ive forgotten several times and had no trouble in the spring. Just what is the actual function of these drains?

    June 5, 201211:23 amReply
  14. studi30

    If you are going to blow out your lines with compressed air, you must not have the pressure above 40 lbs. Higher pressures can rupture water lines.

    December 16, 20152:38 pmReply
  15. wmasscowgirl

    So, the question I have – I have a new camper and it is of an edition that they say you can camp so something like 20 below. I know it is insulated underneath. So – how do you camp in cold weather and still not have lines freeze? No one seems to be able to answer that for m!

    January 12, 20161:51 pmReply
    • William Inglis

      You will heat the camper and the underside is insulated. It would seem to require that you use the internal fresh water tank.

      November 12, 201611:36 amReply

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