How to Heat an RV in Cold Weather and Winter Snow Storms

Heating an RV in cold weather during the winter, especially in a snow storm, is quite different than heating a house, and it often requires utilizing different kinds of heaters and a little creativity too.

A few weeks ago, at the end of September, we woke up to find ourselves in a beautiful snowstorm at 10,000′ elevation in Colorado.

We had to pull out all the stops to make sure we were cozy warm in our RV even though overnight lows were in the 20’s and daytime highs didn’t get out of the 40’s for a week.

The first order of business was to go outside and build a snowman, and Mark got right to it.

While he’s busy getting that snowman together, I wanted to share with you the strategies we’ve used for heating our RV without electrical hookups, because we use different heating appliances in different situations.

For “cool” conditions, like December and February in the Arizona desert or May in the Canadian Rockies, when lows are in the 30’s, keeping our buggy warm is a cinch with our blue flame vent-free propane heater that Mark installed back in 2008.

But in in “extreme” conditions, like this recent snowstorm on a mountaintop in Colorado, we use a different strategy and rely more on our RV furnace that was factory installed in our trailer.

We have tried different strategies in very cold weather at very high altitudes like this in the past, and this most recent cold spell was our most comfortable, despite the wet gloppy mess of snowy covered jackets, hats, mittens and boots and the sullen gray skies that persisted for several days. So, we seem to have gotten it right this time.

Of course, “lows in the 20’s” is far from “extreme” for North Americans living in houses with central heating, but it definitely feels extreme when living in an RV off the grid. In reality, RVs are most comfortable in temperatures that stay above freezing.

Even though high end RVs are marketed as being “four season” coaches, boasting high R-factors in the walls, ceiling and floor, you just can’t compare 1.5″ styrofoam walls that have a thin layer of gelcoat and wallpaper board to a residential house wall that’s made of 3.5″ fiberglass insulation covered with a half-inch of drywall, half-inch of plywood, Tyvek and exterior siding.

Besides the skimpy walls, we find that the RV windows are the biggest reasons for the poor insulation. The metal window frames are extremely cold to the touch when temps outside are in the 20’s, and all that metal around our many windows conducts the cold right into the rig.

Some folks like to have thermopane (dual pane) RV windows, but if moisture gets between the two panes, which can happen more easily in an RV that rattles down the road all the time than in a house that stands still on its foundation, the moisture is likely to remain there permanently, no matter what the weather does outside or how many years go by.

RV windows don’t seal all that well either. Our top quality, four season fifth wheel trailer is downright drafty inside, with a definite breeze that can, at times, flutter a tissue by the “escape” windows. You don’t notice it so much when it is 70 degrees both outside and inside with no wind blowing. But when it is a blustery18 degrees outside and we are trying to heat the rig to 65 degrees inside, the breeze by those windows is a shock.

The microwave vent is another drafty spot, and if the wind is howling outside and blowing directly on that wall of the RV, it blows right into the kitchen through the vent holes on the top of the microwave. One solution for that, of course, is to tape over the vent on the outside of the rig and not use the microwave for the duration of the cold snap (we haven’t done that, however).

So, in our experience, keeping an RV and everything in it toasty warm when it is snowing out can require a little creativity.

Back in our house living days in snow country, we would set the thermostat to our preferred indoor temperature and keep it there 24/7, perhaps raising it slightly at the breakfast and dinner hours and lowering it slightly while we were at work or asleep.

When a blizzard blows into our RV lifestyle nowadays, we can have that kind of stable heat in our rig if we plug into shorepower with access to unlimited electricity. Portable electric heaters can back up the RV furnace, and RVs that have an air conditioner with a heat pump can use that (ours doesn’t).

We have a portable electric ceramic heater for just such an emergency where going to an RV park and plugging in is our best line of defense for weathering a storm.

However, it is possible to stay warm without hookups, even when it starts snowing.

We rely on our vent-free propane heater for 95% of our heat year round. These little heaters use propane very efficiently, don’t need any electricity to run, and can be installed in an RV permanently to run off the RV’s propane tanks.

There are also handy portable models that can be stored in a closet when not in use and then placed anywhere in the rig where you want a little heat. These run on disposable propane bottles, so it isn’t necessary to plumb the heater to the RV’s big propane tanks.

We have a detailed article describing the different kinds of vent-free propane heaters on the market, the pros and cons of each type and the type of heat they generate, plus a step-by-step guide for how to install one in an RV at this link:

How to Install a Vent-free Propane Heater in an RV

These heaters heat the rig amazingly quickly. We find that our 20k BTU blue flame heater warms our rig at a rate of about one degree every two minutes. So, in twenty minutes we can warm up our home by 10 degrees, and in an hour we can raise the inside temp by 30 degrees.

The best part is that we can hover over it and warm our hands, bodies and clothes, just like standing in front of a woodstove or fireplace. We do that a LOT and totally love our little heater for the terrific blast of instant hot air it provides!!!

We use our blue flame heater year round, and we have used it at elevations ranging from sea level to 10,000′.

This past year we traveled primarily in cold places where overnight lows were in the 30’s and 40’s. We went north through Utah, Idaho and Montana in March and April and spent May and early June in the Canadian Rockies. Consequently, we saw quite a bit of snow and hail, and during those months we used our heater almost every day.

We thawed out in July long enough to get overheated and write a blog post: “How to Beat the Heat in an RV.” Then it was back to the high elevations of Utah and Colorado in mid-August where we saw more hail and overnight lows in 30’s once again.

Our vent-free blue flame heater has been keeping us warm during all four seasons like this since Mark installed it in 2008!!

The basic difference between an RV furnace and a vent-free propane heater is this:

• RV furnace – Uses a lot of electricity, uses propane inefficiently, brings fresh air into the rig (because it’s vented)
• Vent-free propane heater – Doesn’t use electricity, burns propane efficiently, uses up oxygen in the RV

So each has its place under certain circumstances. In a nutshell:

— The ventless propane heater is awesome as long as there is sufficient oxygen for it to run. We like to use it in the mornings and evenings, and since we are in and out of the rig a lot, there is a lot of air exchange inside our RV from opening and closing the front door all day long as well as from all the drafts and breezes that blow in the RV windows and microwave vent.

— The RV furnace is best for other scenarios: in cases where there is a risk of the water pipes freezing (the hot air ducts keep the basement and water lines warm), at very high elevations in extreme cold, and at night, because it is vented and continually circulates the air in the rig. The RV furnace is very loud and tends to wake us up at night, however, so we don’t use it overnight very often.

So, we use our vent-free blue flame heater for 95% of our RV heating, and we turn to our RV furnace on rare occasions.

Vented vs. Ventless Propane Heaters and Propane RV Stoves & Ovens – Safety Concerns

An RV furnace is a vented system, meaning that it releases warm, moist air from inside the RV to the outside, and it brings cold air from outside to the inside of the rig. This makes it very inefficient in its use of propane, because it is essentially heating the outdoors as well as the indoors. Put your hands by the RV furnace vent outside, and they will get nice and warm and a bit damp too!

While RV furnaces are safely vented yet very inefficient, vent-free gas heaters are very efficient and are required by law to have an automatic shutoff when the available oxygen goes below a certain threshold (there is a built-in sensor that triggers the shut-off). We know when ours is about to shut off because the flame begins to sputter and make noise. Once it has shut itself off, it won’t turn on again until we air out the RV a little by opening the door or windows for a while.

Ironically, propane RV stoves and ovens are not required to shut off automatically when the available oxygen is depleted. To me, this makes them inherently quite a bit more dangerous than vent-free propane heaters.

Of course, an RV fitted with propane tanks is basically a rolling bomb, so it’s a very unsafe place to call home (I say this with a smile, because we wouldn’t trade our 9 years on the road for anything)!

Every time we have seen our blue flame heater shut itself off (probably 30+ times), the RV stove and/or oven has kept right on a-cookin’ without any hint that our supply of oxygen inside the rig was running out. We could easily have baked something in our factory installed propane RV oven and simmered something on our factory installed propane RV stove for hours while camped at 10,000′ with no inkling that the oxygen in our rig had dipped below safe levels!

Which Heater is Best Under Which Conditions?

For most of this year as we traveled in cold country, the lowest temperatures we saw were in the low to mid 30’s overnight. Daytime highs were in the mid-60’s to mid-70’s. These kinds of conditions are very similar to what we see in the southwestern deserts in the winter months (except January, which can be colder). These conditions are ideal for a vent-free propane heater.

We usually run our vent-free propane heater every morning until the rig is 60 to 75 degrees inside (depending on our mood) and then again in the evening if the temperature inside has dipped below 65. If the windows have fogged up from condensation (about 5% of the time, usually only in the winter), we run the RV furnace too to help dry the air out.

In general, we don’t heat our RV overnight in this kind of climate. We prefer to bundle up with down comforters instead. If we do run the heat at night, we use the RV furnace and set it to 50 degrees. If outdoor temps drop into the 30’s overnight, the RV furnace will come on once or twice in the pre-dawn hours.

Ironically, if the outside temps dip really low — into the 20’s or teens — and daytime highs don’t get much past 50 degrees, then the RV furnace will start coming on before midnight and will come on every hour for 15-20 minutes as it struggles to keep the rig at 50 degrees.

Since we are light sleepers, this is extremely annoying. So, at the times we would want to run the RV furnace most — overnight when it’s really cold — we opt not to!

On overnights that we don’t heat the rig, when we wake up in the morning our bedroom is around 10-12 degrees warmer than the outside air (bedroom door closed all night) and our living area is around 5-7 degrees warmer than the outside air.

It is routine for us to wake up to temps in our trailer that are between 37 and 42 degrees. For us, that is a small price to pay for living off the grid, however, for many RVers it is good reason to get electric hookups and have more substantial and consistent heat in the rig overnight.

There is a lot of debate about whether you can operate a ventless propane heater at high elevations. By the time we got caught in that September snow storm in Colorado two weeks ago, we had been living at elevations between 8,000′ and 10,000′ for 5 straight weeks, running our vent-free propane blue flame heater every morning and evening without a hitch.

Along with many weeks spent heating our rig at high elevations in previous years, including 8 weeks or so at 6,000′ or higher this past spring, our 5 weeks at 8 to 10 thousand feet this fall kind of proved the point for us: it’s no problem to run a vent-free propane heater at high altitudes in cool weather.

But in sub-freezing overnight temperatures and daytime highs in the 40’s under stormy skies at 10,000′ elevation, we’ve found a vent-free propane heater is best used in combination with the RV furnace.

Until the the snowstorm came to our mountaintop spot in the Colorado Rockies at 10,000′, we hadn’t been using the RV furnace at all. But once the temps dropped to the 20’s (lows) to 40’s (highs) at that elevation, we couldn’t rely on our blue flame heater exclusively any more and had to change our heating strategy for three reasons.

1) There is less available oxygen at 10,000′ than at lower elevations, and once the oxygen in the rig dipped below a certain level, the blue flame heater would shut itself off automatically. Because it was so cold outside, we weren’t thrilled about opening the windows and doors to let in more air just so we could turn on the blue flame heater again. It was time to use the RV furnace.

2) Our RV roof and ladder — along with our solar panels — was covered with snow and ice. Mark wasn’t jumping up and down with excitement to climb up there to clear off the solar panels, and I wasn’t about to get up on that slippery roof either. So, our batteries were no longer getting charged by the sun and wouldn’t have enough juice to run the RV furnace.

3) Vent-free propane heaters emit a lot of moisture. We had just had several days of torrential rain, and everything in our rig was wet. Our shower was filled with raincoats and rain hats hung up to dry, our boots and socks were wet and muddy by the door, our pants were wet and hanging in the bathroom and our bath towels refused to dry. While our blue flame vent-free heater would exacerbate the moisture problem, our RV furnace would help dry out the air inside our buggy.

Doing all these things gave us a nice dry and toasty warm environment to live in during this cold spell in snowy conditions at 10,000 feet.

To implement this heating strategy, we did two things. We stocked up on gasoline and propane and ran our Yamaha 2400i generator and RV furnace a lot. Sometimes we also ran the blue flame heater alongside the furnace.

The generator ensured that the batteries got fully charged. Because we were running our RV furnace so much, which burned up lots of electricity, the batteries were being depleted much faster than normal. So, not only did we need the generator because the solar panels were snoozing under the snow and ice, we also needed it because of running the RV furnace.

In general, we ran the RV furnace every morning until the rig was 65 degrees inside and then ran it on and off during the day and in the evening. If the air wasn’t too moist, we also ran blue flame vent-free heater alongside the furnace to warm things up faster. The vent-free propane heater never shut itself off, so the RV furnace was doing its job of circulating the air.

Using the RV furnace also lessened the possibility of the water pipes freezing. The heater is ducted through the belly of the rig, and the warm air passing through the ducts helps warm the nearby water and sewer pipes. If the temps had gotten below 20 degrees, we would have run the RV furnace once or twice overnight as well just to be sure no ice formed in the pipes.

If we had had brilliantly sunny days every day, we may or may not have needed the generator. Our 490 watt solar panel array may have been able to charge the batteries fully, despite the additional load from the RV furnace.

Also, we probably wouldn’t have needed to use the RV furnace so much because the sun would have warmed up our rig and dried it out a bit during the day.

See how flexible and variable all this is??!!

We have descended out of the clouds now and have been living at elevations between 5,000′ and 6,500′ for the past few weeks. The RV furnace is back on vacation and our trusty blue flame heater has taken over all the RV heating duties. Our generator is on break for another 6 months or year, and the shore power cord is buried somewhere in the basement once again.

If you are going to be using your RV in cold weather this winter, we have another post full of tips for keeping warm that you might enjoy:

How to Stay WARM in an RV – Winter RVing Survival Tips

And if you think a vent-free propane heater is something you’d like to get, have a look at our detailed article that discusses the different types of heaters and shows how we installed ours:

Vent-free Propane Heaters (Catalytic, Infrared and Blue Flame) PLUS How to Install One in an RV

Subscribe
Never miss a post — it’s free!

For more images of the Colorado fall colors in the snow, see this post:

• Brilliant Fall Foliage + Snow in Colorado’s San Juan Mountains – 11/22/16
• San Juan Mountains in Colorado — And then it SNOWED!! – 10/25/14

 

Our most recent posts:

• Beehive Trail in Arizona – A “Mini Wave” hike by Lake Powell 07/19/24
• Reese Goose Box Review: 20K Gen 3 TESTED + How to Hitch 06/27/24
• Lake Powell – Heart of Glen Canyon National Recreation Area 05/10/24
• Quick Release Pull Pins for Fifth Wheel Landing Jacks – YES! 05/03/24
• Sheep May Safely Graze (in the Mountains with Dogs!) 04/26/24

More of our Latest Posts are in the MENU.
New to this site? Visit RVers Start Here to find where we keep all the good stuff!!