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  • Writer's pictureBill Lindemulder

Winterizing your RV Checklist

Updated: Oct 18, 2023

winter storage of motorhome

It’s that time of year again when RV owners think about winterizing their trailers and motorhomes. Wild Mountain RV used to be located right next to a large RV storage lot, and as a result we did hundreds of Winterizing each year on location. As the owner, I had the most flexible schedule, so I did all the winterizing. To keep things consistent, we created a procedure checklist that we still use today. Before I share this checklist, here are a few other things we have learned over the years:

Antifreeze vs. Blowing Out Lines

Deciding whether to use RV antifreeze to winterize your RV or blow out the lines is strictly a personal preference. Whenever this discussion comes up, you are going to hear the line “I have been blowing out my water lines for 20 years and never had a problem”. Even though I don’t doubt anyone who makes this statement, we always recommend the use of RV antifreeze for winterizing for the following reasons:

  1. I have many stories of freezing damage on RV’s that had the lines blown out. One that stands out is from a former employee who used to work for a large RV rental company here in Calgary. One year they made the decision blow out lines in order to save money on the price of RV antifreeze. As a result, they had a large percentage of their fleet incur water damage and in need of repairs the following spring. They used RV antifreeze every year after that.

  2. Air will never get all the water out of your lines, and depending on how your lines are routed, water will settle into the low points. If the water is just sitting in Pex lines, it shouldn’t be a problem, but if water settles at any plastic fitting or valve it will most likely crack.

  3. Lastly, RV antifreeze has a lubricant in it that prevents rubber seals from drying out. This is important in your faucets and even more important in your water pump. Running antifreeze through your water pump will ensure a longer life.

When to Winterize?

This is the most common question we get. In reality there is little risk of damage to your water system if the average 24-hour temperature is above zero degrees Celsius (in other words, take the overnight low and add the daytime high and that number should stay above zero). With that being said, I have encountered frozen water lines in -3 degree temperatures. Even though the water will freeze (will not flow) at this temperature, rarely will this damage your water system. It usually takes sustained freezing temperatures to cause damage. Personally, I suggest winterizing before the overnight lows reach negative temperatures (Celsius).

Winter thermometer

What do I do if I can’t winterize before the temperatures drops?

If you don’t have the time, or don’t have antifreeze, and you know the temperatures are going to drop, there are a few things that you can do to prevent (or reduce) damage in the meantime. Make sure your water heater and fresh tank are drained. Open any low point drains (if you have them). Release the pressure from your water system. To do this, make sure your water pump is off and open/close all your faucets and operate the toilet flush.

I forgot to winterize my RV!

If you forget to winterize and your RV freezes up solid, don’t feel bad; you are in good company! (yes, including me 😊) The biggest worry when forgetting to winterize is the water heater. This is why it is important to always drain your water heater when it gets late in the season just in case you forget to winterize. This is by far the most expensive repair you will have; they are rarely spared when frozen solid. Most RVs manufactured in the late 80’s and beyond use Pex for the water lines. Rarely will Pex split from freeze up. The faucets, shutoff valves, and toilet valve will usually crack before any lines are damaged. Many very old RVs use different materials for water lines, and most of these are susceptible to cracking, so if you have water lines other than Pex, ensuring you winterize is even more important.

Do not ignore your frozen RV; still get it winterized. Because the water lines are likely to thaw and refreeze many times over the winter, the damage will only get worse. Here at Wild Mountain RV, we book in frozen trailers and bring them into our shop overnight to thaw – we then can winterize the RV and check for damage.

What type of antifreeze to use?

This may sound ridiculous to even point out, but we have heard of RV’s accidentally winterized with automotive antifreeze. This is understandable for someone who is not aware that there is a difference between automotive antifreeze and water system antifreeze. Automotive antifreeze is toxic, so ensure you have water system antifreeze and better yet, antifreeze specifically designed for RVs.

Some people don’t like the smell of RV antifreeze, and some say it leaves a taste in the water. I would not know because personally we don’t use our RV water system for drinking water (just cooking and washing). There are some more expensive brands of RV antifreeze that advertise less odor, but these usually do not have the lubricant additive that I mentioned earlier. I am not aware of any advantage from one brand of antifreeze to another brand.

Procedure Checklist

Below is a link to the Winterizing Procedure Checklist used here at Wild Mountain RV. Feel free to download a copy. You should be able to find detailed information online on how to perform each step if you are unsure. Here is the basic procedure:

  1. Drain water from water heater and fresh tank (ensure your waste tanks are empty as well)

  2. Bypass water heater (you don’t want antifreeze to run into your water heater so the bypass ensures the antifreeze flows past)

  3. At the water pump, disconnect the water tank supply hose and connect a section of hose (or use a preinstalled winterizing line) and put the other end of the hose in the antifreeze jug.

  4. Turn on the pump and open each faucet (hot then cold – or cold then hot) until pink antifreeze flows out and shut off. Operate the toilet until pink is visible.

  5. Turn off the pump and release the pressure in the lines.

  6. Pour antifreeze down each drain to fill the p-trap, and some extra to flow down to the drain valves (just in case there is residual water at the valves)

Winterizing Checklist
Download PDF • 103KB

What else do I need to do to winterize my RV?

  1. The most important other thing for winterizing is to remove all food and traces of food to prevent attracting rodents (mice!).

  2. Leave your fridge and freezer door open to prevent mould growth.

  3. Batteries – many differing opinions on this one – this is my advice, but others may disagree and I’m always open to correction. The bottom line is that a fully charged battery will not freeze, so you need to ensure the battery is charged all winter:

    1. I have solar and I leave my batteries in my RV and connected during the winter. I would agree the best procedure is to take them out, but I have never had a problem with leaving them in and connected to solar.

    2. Ensure your batteries are fully charged (should read approximately 13 volts or more on a voltmeter). Disconnect the negative cable and leave them in your RV. I usually suggest checking the voltage a few times throughout the winter to ensure they are keeping their charge (they should if they are still good). If you find the voltage dropping to below 12.5 volts, they should be charged up.

    3. Remove your batteries and store them (fully charged) in your garage or other out of the way location. They do not have to be stored on wood, that is something that was true in the “good old days” not with today’s current batteries. Once again, if they are kept in an area that gets down to freezing temperatures, ensure you check their voltage level a few times during the winter and top up if they go down.

    4. Trickle chargers – you have to be careful with this!! Many battery trickle chargers are not designed for deep cycle batteries, and can result in over charging batteries, which in fact can be more damaging to batteries than freezing. If you use a trickle charger, I recommend charging the batteries to full then disconnecting the charger and checking the voltage a few times during the winter to see if you they need a ‘top-up’.

  4. Sun exposure. If you have the option to decide which direction your RV will face during the winter, please keep in mind that anything facing South will be exposed to the most directly UV rays (due to the location of the sun) and thus most susceptible to UV damage. Tires, awnings, decals, and paint are most affected by direct UV rays in the winter.

  5. RV covers are not typically used in our area. This is mostly because there is a risk of humidity buildup due to the many shifts in temperature we experience during the winter. If you decide to cover your RV, ensure you buy a good quality cover that ‘breathes’ to prevent humidity, and also one that it is tight (secured well). I have seen a few examples of paint damage from flapping RV covers.

There are a number of other procedures some people do to winterize their trailers, but this sums up what we recommend to our customers.

If you would like to book in a winterization with Wild Mountain RV call or email us today!


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