So it is getting cold, let’s talk about winterization of your RV’s water system.

Q: When should I winterize?

A:  Here is my take: As a 16 yr RV owner, I will call it quits and winterize once wind chill gets to 28 degrees. Or ambient temp of 30 or less for more than 5 hours, unless you have tank heaters, etc.

First off, take an inventory of EVERYTHING in your RV that uses water, as you will want to do some prep work, here is a starter list.

  • Most common water stuff in a RV
    • Bathroom(s) sink(s)
    • Freshwater tank
    • Indoor shower
    • Kitchen sink (indoor)
    • Toilet(s)
    • Water faucets
    • Water heater
    • Water pump
  • Not as common
    • Dish washer
    • Ice machine in freezer
    • Kitchen sink (outdoor)
    • Outdoor shower
    • Washing machine
    • Water faucet at refrigerator
    • Water filter(on board) and possibly in your refrigerator.

Print out the list above and mark which ones you have or line out the ones you don’t.

Second determine how you want to winterize, I recommend using the RV Antifreeze method, almost any RV Dealership, and on Amazon🙂 but others recommend the “use air to blow out my lines method”.  I don’t like the air method as I don’t care to push air from some tank where I have no idea what is in it, rust, dirt, etc., so I stick with the “pink” stuff method, has worked for me for last 16 yrs, I’ll stick with it.  So this post will be based on that method, so if you are looking for the “air blow out the lines method”, you probably want to quit reading at this point.

How many gallons of RV/Marine anti-freeze do you need?  It entirely depends on how many appliances you will need to winterize, I can get away with 2-3 gallons, but if you got a large Class A with dishwasher, washing machine, etc, you will need more, on those I’ve used as much as 4 gallons.

Prep Work

Tank Water Heater

  • Have water pressure turned on, either your water pump or city water connection.
  • Turn off both propane and electric to the water heater.
  • Turn on faucet hot water side and run until the water is cool in all of the faucets, you are just getting rid of the hot water from the tank and the lines.
  • Turn off city water and/or freshwater pump.
  • Open a faucet, one more time to relieve pressure from the lines, both hot and cold water sides.
  • Begin the process to find your water heater by-pass(assuming you don’t have one of those fancy tankless heaters), see where your water heater access panel is on outside of your RV.  Most look something like this(you might not have a screen on yours), twist the “lock” on top and open up the water heater.  Mine looks like picture #2.
  • Now that you know where it is outside, go back into your RV and figure out how to access the back of the water heater from the inside.
  • It could be under a bed, under a sink, behind an access panel under sink in bathroom, the list goes on and on, mine is in a convoluted place that I have to be a contortionist to get to.
  • Once you have found the back end of it, there will normally be some valves known “BYPASS” valves.
  • Let’s think about this, what you are attempting to do is STOP WATER GOING INTO THE WATER HEATER
  • Keep in mind normally the way the valve is pointing is the way the water WILL FLOW.
  • There are a few configurations, let’s take a look at the most common ones:
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  • 3 VALVE PICTURE(below):  So to keep water from flowing into the water heater, in picture with 3 valves, we want top valve turned so it is NOT inline with the red(hot) water line, same for bottom valve(blue/cold water line).  Now what do we do with the middle one?, make sure it is pointed inline, this way the water flows in the cold line, hits a closed valve on the blue line, goes up the vertical line (blue to red), hits the top and can’t go to the right since it is closed and goes to the left through the hot water line to the rest of the RV.  NO WATER GOES INTO THE WATER HEATER is your objective.  This picture is just a mess, it is NOT set for bypass mode and not set correctly for normal mode, it is just a mess.   Do you know why?
  • ———————————————————————————————————————————-
  • 2 VALVE PICTURE (below):  Put BOTH valves inline with the water lines, so the water goes through the half circle line to the right and never goes into the water heater, this picture shows it in bypass mode.
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  • 1 VALVE PICTURE:  The only valve on this one is at the bottom and it points the way the water will flow, it is currently set to allow water into the water heater, turning it so the handle on it points upwards will make the water flow up the bypass and not into the tank.  So how does the top part not allow the water to go into the top of the water heater?  There is a check valve that only allows water to flow one way out from the top.  This picture shows it in normal mode, NOT BYPASS MODE.
  • ———————————————————————————————————————————-
  • So you can see this can be confusing but if you just remember you don’t want any water going into the water heater, it should make sense.
  • Now some one you have one of those fancy type water systems, that might have a simple switch to flip at the water control center to put things in bypass, just be sure to read the directions very carefully as the switches one way mean one thing and you are looking for water heater bypass settings.
  • Now that you have water heater on bypass, at lower left of most water heaters, is a plug, some of your will have a anode(Suburban water heaters) and some of you will have probably a plastic plug(Atwood water heaters), remove it and DRAIN THE WATER HEATER NOW(we will talk about flushing the water heater later), just let it run to the ground (you did run water earlier to make sure it is not hot, right???)

Tankless Water Heater

  • Follow your owner’s manual on how to winterize it, it is slightly different depending on the model.  Make sure you read the parts above just for understanding as you might have one of the models that has the switches for doing bypass.

Water Filter

  • Locate the water filter system(s).
  • Remove the filter casing(that hold the water filter, you might need your wrench to get it loose).
  • Remove the water filter.
  • Replace the casing.
  • If you have a refrigerator that does water dispensing and/or an ice maker, be sure to check and remove their filters if possible, you don’t want the pink stuff in the filter, otherwise you WILL be replacing them in the spring.

RV Antifreeze

How do we get the “pink” stuff in your water lines WITHOUT PUTTING IT IN THE FRESHWATER TANK?

How many gallons do you need?  It entirely depends on how many appliance you will need to winterize, I can get away with 2-3 gallons, but if you got a large Class A with dishwasher, washing machine, etc, you will need more, on those I’ve used as much as 4 gallons.

This for some will be easy for others a bit more complicated and for some it will require you to do a bit of work.  Let’s tackle the easy part first.

  • Drain your freshwater tank NOW.
  1. Easy:
    • You remember the picture above, you flip some levers and then the same place you would hook up city water/freshwater and the levers are set right, will pull from a hose in the gallon of pink stuff.
  2. Only slightly more complicated:
    • See if you have a valve near the water pump (yes you will need to find your water pump) and an extra hose that will let you connect up to bottle of pink stuff.  Mine is like that I have two valves, one turns off access to pump from the freshwater tank and another one to pump from a hose which I put in the gallon of pink stuff.
  3. More complicated:
    • You don’t have a line to be able to pump from pink stuff, you can then get yourself a hose and connector that would match the INPUT of the water pump, disconnect the input side from the freshwater tank that connects to the water pump at the water pump side, hook up the new house to the pump and other end in the gallon of pink stuff.
  4. Last option:
    • Install a kit so it becomes easier in the future, I did this for my 1987 Mallard, make winterizing a breeze, then you can do #2 above.

Got some other setup for water heater bypass or it appears no way to get pink stuff in(are you sure you can’t do #3 above), feel free to send pics to put in subject line WINTERIZATION and I’ll take a look and we can talk through options.


Ok so now you have a hose in the pink stuff, the other side connect via one of the four options above and we’re ready to get the pink stuff flowing.

It is usually easier to do this with two people, one watches the pink stuff level in the bottle and the other person goes around and opens faucets, etc but if there is only 1 of you, it can be done a couple of different ways:

  1. Get a 5 gallon bucket pour a couple of gallons of pink stuff in it and put the end of the hose in there OR
  2. After you run the pink stuff out of the one gallon container make sure it has NOT run out, if so, turn off pump, and move hose to new full container.

First off, make sure you are ready to pump pink stuff in your system, turn your water pump on, NO FAUCETS OPEN YET.  Let it run till it stops, now your system is pressurized, the cold and hot water lines.

Faucets:  For EACH water faucet, run the cold until you see pink and then the hot until you see pink, turn that one off.  We will do the most common items first.

  • Bathroom:  Sink, Shower, Toilet
  • Kitchen: Sink
  • Outside:  Kitchen sink, Shower

Check the level of your antifreeze in the bottle as you open and close each faucet.

For most of you, you are probably done but for some there are a few more items you might have.

Dishwasher: You will want to run the dishwasher enough to see that you got pink stuff in the bottom, so just start the fill process, keep checking till you see pink and then run the empty out process.

Washing Machine: Begin a wash cycle till you see pink stuff, then run the drain/spin cycle to get rid of the pink stuff.

Refrigerator Water Dispenser:  Make sure to have removed the water filter if there is one and then run the water dispenser into a cup until you see pink stuff, the idea to is make sure there is only pink stuff and all water is out.

Freezer Ice Cube Maker:  This one could be a bit tricky, depending on your ice maker manufacturer, it is best to check the owner’s manual to see how they say to winterize, sometimes you have to let it run a couple of ice cube cycles, other types have a spot you can trigger the water to flow through without having to go through cycles.

Added: Oct 2022: One last step before turning off water pump, open the low point drains, hot and cold one at a time, to drain water from them also.

Almost done, we’re done pumping pink stuff, turn off water pump, consolidate your partial bottles of anti-freeze, save for next time(yes they can sit out in the cold in your garage, etc until next fall with no degradation).

Take some of the anti-freeze, pour into EACH AND EVERY DRAIN, to wash out any water still in there to the tanks and it will fill the p-trap with some antifreeze.  

Ok I mentioned earlier flushing of water tank, you already have the plastic plug or anode rod removed from the water heater tank, get yourself one of these: Water Tank Flush Wands

and hook it up to a garden hose, put it in the place where the plug or anode rod was, spray all around in there and be ready for gunk to come rushing out.

You are now done winterizing your RVs water system.

Want to know more, check out this podcast:

Questions, comments, want to chat about this?  All of my contact info is at the top of the website.