Monday, December 4, 2023


Fact or Fiction? If you see these on your RV, do not use it in winter (Answer)

Answer: Fiction
Let’s take a look at the problems/assumptions contained in this statement: “If you can see holding tanks underneath your camper, you should not use your trailer for winter RV camping.”

Before I get started, let’s first clarify the beginning portion of the statement: “If you can see holding tanks underneath your camper.” The author is referring to the black, gray water, and possibly the fresh water holding tanks being exposed to the elements underneath the RV. This is as opposed to holding tanks that are enclosed, and sometimes heated by the furnace, within the underbelly or interior of the RV.

Wrong assumption

The first problem is the assumption that “winter RV camping” equates to camping in freezing weather. As we all know, temperatures of 32° F or lower will cause water to freeze. Freezing water expands, which can cause damage to the receptacle containing it. In this case, the container holding the water is your black, gray and possibly the freshwater tank located below the floor of the enclosed heated space of the RV’s interior.

Many RVers, including myself (in Western Washington), live in temperate areas that seldom experience freezing weather in the winter. This alone negates the statement, “If you can see holding tanks underneath your camper, you should not use your trailer for winter RV camping.” If it isn’t freezing, there isn’t a chance of damaging your exposed holding tanks.

A more correct statement

A more correct statement would have been: “If your holding tanks are exposed, take these precautions when RV camping in freezing weather.” Then point out the following:

A) If temperatures only dip below freezing for a few couple hours at night, there is little chance of damage occurring as there are only two possible scenarios: 1) The holding tanks have little in them. In this case, if the contents were to freeze there is plenty of room for the freezing contents (water) to expand without causing damage. 2) The holding tanks are nearly full. In this case, a few hours of freezing temperatures will be incapable of freezing the large volume of material in the tanks. This applies to underfloor freshwater tanks as well.

B) The installation and use of holding tank heaters on exposed holding tanks will prevent freezing, allowing winter RV camp during extended periods of freezing weather.

C) RV antifreeze can be added to holding tanks to prevent the contents (primarily water) of the holding tanks from expanding and freezing solid. This is not applicable to underfloor freshwater tanks.

D) Many RVers opt to keep their RV winterized while camping in freezing weather, using campground restrooms and shower facilities rather than those in their RV. With no water in the plumbing system to end up in the holding tanks, there is no chance of freeze damage.

As Editor Chuck Woodbury pointed out recently, there is much “misinformation out there created by artificial intelligence (AI) robots and content creators who know nothing about RVing, yet pretend they do.” Hopefully, with the help of readers like you, we call out the bad information, while providing an accurate rebuttal.

Now, some questions for you:

  • Is there a reoccurring half-truth you keep seeing online that you would like to see addressed?
  • Were you taught something by other RVers that turned out to be bad advice?
  • Have you recently read something that left you wondering, is that true?
  • Do you know something to be true, but none of your RVing friends believe you?

Please share your comments using the comment box below and we will do our best to provide the facts in a future Fact or Fiction entry.


Dave Helgeson
Dave Helgeson
Dave Helgeson has been around travel trailers his entire life. His grandparents and father owned an RV dealership long before the term “RV” had been coined. He has served in every position of an RV dealership with the exception of bookkeeping. Dave served as President of a local chapter of the RVDA (Recreational Vehicle Dealers Association), was on the board of advisors for the RV Technician Program of a local technical college and was a board member of the Manufactured Home and RV Association. He and his wife Cheri operated their own RV dealership for many years and for the past 29 years have managed RV shows. Dave presents seminars at RV shows across the country and was referred to as "The foremost expert on boondocking" by the late Gary Bunzer, "The RV Doctor". Dave and his wife are currently on their fifth travel trailer with Dave doing all the service, repair and modifications on his own unit.



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KIRBY MARCHAND (@guest_257819)
1 month ago

Is it safe to run your refrigerator on propane while traveling? I personally don’t think so but I see many people on social media saying that they were designed to be run on propane while traveling. My Owner’s Manual says it is unsafe.

Richard Hughes (@guest_227074)
8 months ago

Having lived at 7,600 feet in Colorado for nearly 40 years, from Oct. To July, exposed pipes and tanks could freeze at any time. Winter camping there meant a freeze was pretty sure to happen.

Steve Willey (@guest_227073)
8 months ago

For winter camping, the purpose is to ESCAPE from the coldest areas. Stay on low elevation roads whenever available. But you can also dump a gallon of RV “pink” antifreeze in the holding tanks or flush toilets with that stuff. If freshwater tanks are inside AND PIPES ARE INSIDE, that can work for kitchen and sinks. But often some pipes run under or within rear walls where no heat can be applied, such as behind the shower stall. I was able to cut a vent into the rear wall and run a small fan or 200 watt heater into those areas, but the shower stall itself, against the rear wall, can be a freezing problem. If headed south, we can wait to fill the water, using gallon jugs at the start of the trip. Despite all this, we had one freeze-up we could not avoid, right in the heart of sunny Texas!

George Farewell (@guest_227063)
8 months ago

If anything in the holding tanks freeze, it’s an absolute nightmare to clean them out.

Gary Bate (@guest_227060)
8 months ago

Even exposed under the chassis tanks and valves/drainage system are still warmed and protected somewhat by the heat or warmer temperature of the interior of your RV’s. We’ve never camped in consistently below freezing temps and wouldn’t choose to. We have hit well below freezing temps a couple of times but had no issues I was confident that the limited time of exposure and the additional warmth from above would help. We do have a heater button for the black tank but I’ve never used that. 2009 Winnebago View.

Lisa Harris (@guest_226929)
8 months ago

We have a little Class B with few “bells and whistles” but still have amenities. Also, not full-time RV’ers, but tourists along the way. There is a 30 gal water tank inside the vehicle under one of the “beds” or seats. Even so: Wintertime traveling from AK through the YT in Canada to get to the Lower 48 (and usually taking the longer route–AB, SK, MB to MN or Niagara NY) we have experienced temperatures below the -40 degrees F. where the lower end of our thermometer pegs out. We carry our drinking water in a 5 gallon “jug” in deep winter to keep from ruining our water pump. And try to keep the gray tank as dry as possible. Doubt that’s being “over-cautious” under the circumstances. In our previous van those “little buddy” etc propane jugs froze and of no use until treated like hatching eggs. I have to chuckle when van-dwellers on-line complain their friends advised floor insulation wasn’t necessary. Won’t comment on engine block heaters, battery blankets etc. It’s all relative.

Spike (@guest_226861)
8 months ago

(B) It’s not a given that exposed holding tanks with heaters will not freeze. That assumes you have power to keep them running and that really cold extended ambient temperatures will not overcome the minimal heat from those electric pads. I have winter camped in conditions below zero where I would never trust a heat pad on an exposed tank.

(C) Adding RV antifreeze to a holding tank: We all know that -50 RV antifreeze, undiluted, freezes at around 10 degrees F. While it doesn’t expand yet at that temp, just how much dilution can it take before it’s worthless? I’ve seen this recommendation many times but NEVER with a statement of how much might be needed in a mix to actually prevent freezing.

IMO this article also makes false or misleading assumptions. Net is, each RVer has to know the physics of their situation and act accordingly. “D” is the safe answer. A, B, and C all carry risk, especially on exposed tanks.

SDW (@guest_226817)
8 months ago

There’s another situation you have to consider. If you’re camping in high elevation, even in the summer, It tends to get below freezing lots of nights by midnight. Leaving 7 more hrs. for water to freeze. This happens in Yellowstone a lot, since you’re rarely below 5 or 6 thousand ft. of elevation.

Ed Fogle (@guest_226810)
8 months ago

I wonder about the thinking a low level in a tank protects it from damage due to freezing. Yes, the tank might be safe but what about the dump lines and valves. They are probably full.

Camper Jack - MyRVRadio (@guest_226857)
8 months ago
Reply to  Ed Fogle

Was just thinking about this, considering posting a comment to this effect.

George Farewell (@guest_227064)
8 months ago
Reply to  Ed Fogle

Correct – and if frozen, fugedaboudit.

Ray S. (@guest_241066)
5 months ago
Reply to  Ed Fogle

Right on Ed! It’s the dump valves and their piping that freezes long before the tanks. I witnessed the busted up piping on several campers in a Fort Davis Texas campground in February 2021 when the Polar Vortex came through. If your dump valves are exposed then your camper is not 4 seasons rated. After seeing all that damage, I will always make sure I buy 4 season rated campers.

Last edited 5 months ago by Ray S.
Keith Goldsmith (@guest_226788)
8 months ago

Considering the education levels of most campers on how to use their unit in any weather let alone winter I vote for them to stay home.

Joe Allen (@guest_226760)
8 months ago

Buying new solves all the issues with problems with your purchase! Wrong! Never buy new, never! First off, you lose 20% right off the purchase, then 10% a year for at least 10 years. Yes, I know, your RV is worth zero and in most cases, it is! Wake up America! Buying used is a great value with less stress and easier on your budgets.

croscwa (@guest_226736)
8 months ago

Two comments:

  • the contents of these tanks aren’t pure water. The freezing point of these is lowered by the substance mixed in; that substance is acting like an anti-freeze. Google ‘freezing point depression’.
  • these tanks are rarely full and have room for the water to expand.
George Farewell (@guest_227066)
8 months ago
Reply to  croscwa

Think about this – why do boat owners hang rubber tires around their hulls when the lake water is going to freeze? Doesn’t the lake have room to freeze UP? Yes, sure, and it does some of that, but it also freezes OUT. Outward freezing can and does crack holding tanks.

Cancelproof (@guest_227082)
8 months ago

Which is why venting is important. When liquid freezes it expand in all directions, if 3 or 4 directions are blocked all the force is directed towards the vent or open side. This is why a glass in water in your freezer doesn’t break when frozen, it expands up, not outward, but a sealed glass bottle of water will break because no venting is available for expansion.

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