Heater Comparison; Mr Heater Buddy versus Olympian Catalytic Wave 3

From left to right you can see the three sizes of Mr. Heater Buddy heaters. On the left is the Big Buddy, next is the Buddy Heater and then is the Little Buddy. To the far right is a Coleman catalytic heater which is a very nice little heater.

From left to right you can see the three sizes of Mr. Heater Buddy heaters. On the left is the Big Buddy, next is the Buddy Heater and then the smallest, Little Buddy. To the far right is a Coleman catalytic heater which is a very nice little heater. The Buddy Heater I’m touching has a filter installed and is hooked up to a 20 pound bottle. Chose on size.

It’s that time of the year again when the memory of warm summer days are quickly fading from our minds and the thoughts of cold, shivering nights are rushing in to replace them, filling us full of dread! But, today I have good news! Living the life of a Nomad on wheels goes a long way to solving that problem!

At one time my life was ruled by the time-clock but fortunately those days are gone forever!! Today my life is ruled by my own internal thermostat, if the temperature isn’t what I want it to be, I just turn the key and drive away  to where it’s more to my liking! In the vandwelling/RVing world that’s know as being a “Snowbird” because we fly away with the weather and seasons.

Of course many of us aren’t in the position to be mobile yet; you may be living in a van or RV but family or economic circumstances require you to stay where you are and that just happens to be a cold area. I totally understand that! After my divorce I couldn’t afford to rent an apartment so I moved into a van, but there was no way I was driving away from my young children! So I lived in a van for 6 years in Anchorage, AK and I learned to adapt to living very comfortably in a van in extreme cold. It can be done and you can be comfortable!

To help you prepare, in today’s post I’m doing a comparison of the types of heaters commonly used by vandwellers. In future posts I’ll tell you how to connect your Mr. Buddy Heaters to a bulk, refillable propane bottle and when to use the filter. In particular I’ll show you how to connect the smallest Little Buddy heater to a bulk bottle because it’s more complicated than the others.

Vented Portable Heaters versus Non-Vented Furnace

To start. Let’s compare the main types of heaters, vented versus non-vented. Take a look at this chart and you’ll see the pros and cons of each and you can let your circumstances make the decision for which is right for you. Your budget and skill level will be the main factors. The portable heaters are cheap to buy and super easy to install and a forced-air furnace is just the opposite; it’s expensive and requires a high skill level. But, if you bought an RV and it already has a furnace, the decision is made for you.


The bottom line is that most vandwellers are going to be much better off with a non-vented, portable heater because they are much smaller and cheaper to buy and operate and equally easy to install.

Are portable heaters safe?

Your first question will probably be, “Are they safe to use in my van or tent? Will I die from carbon monoxide poisoning?” The simple answer is yes they are all safe if used properly and you will not die from carbon monoxide poisoning. You may think you don’t like the caveat “if used properly” but that applies to every fuel burning appliance. They all have the potential to become deadly if used improperly. The key thing with portable heaters is to follow the manuals instructions of ventilation and clearances around it exactly! But, that can be said for every fuel burning appliance. All of these heaters come with a low-oxygen sensor and accidental tip-over switch with auto shut-off to guarantee your safety. If you follow the manual and give them adequate ventilation (usually just lowering your front windows by several inches is enough–but don’t guess, read and follow the manual!) you will be totally safe! It’s also an extremely good idea to add a carbon monoxide detector to your rig. Get a marine grade one from Amazon here: Marine Technologies Combination Carbon Monoxide/LP Gas Alarm

Won’t opening the window offset the heater and leave me colder?

No it, won’t! Even the smallest of these heaters put out much more heat than will come in by giving them adequate ventilation. You can leave the windows slightly open while the heaters turned on and you’ll be toasty warm. Once you turn the heater off you can then close the windows and retain the heat they put into the van. The thermal mass of the van and its contents will continue to radiate heat over night so if you run the heater before bedtime and adequately insulate the van, it should be surprisingly warm the next morning.

The little Buddy is the smallest and because of that I think it's the best one for most car and van dwellers--unless you live in extreme cold.

The Little Buddy is the smallest and because of that I think it’s the best one for most car and van dwellers–unless you live in extreme cold.

A comparison of the heaters:

Mr. Heater Big Buddy Portable Heater: There are three sizes of Mr. Heater Buddy Portable Heaters  and this is the largest, most expensive, and puts out the most heat with three heat settings, 4000-9000-18000.  Because of its high heat output, I know several people that use these to heat their RVs instead of the furnace that came with them. One couple I know heats their 35 foot 5th Wheel with one and greatly prefer it to the built-in furnace. It’s ideal for RVs because of its higher heat output and yet some vandwellers chose them for their other advantages:

  • They use their own regulator so they don’t need a filter like the others do and are less likely to plug up and need a repair.
  • They come with a Quick Disconnect so they are easier to hook up and disconnect then move around or even take it outside using the green, one pound bottles.
  • They come with a built in fan so if you have a larger rig you can spread the heat around inside your home. The fan runs off D batteries or an AC adapter.
  • Having a greater variety of heat ranges allows the heater to grow with you. If you start in a van but then move up to a larger rig like a travel trailer this heater will work for both; using the 4000 btu setting for a van and the 18000 btu setting for the RV.

Mr. Heater Portable Buddy Heater: This is the middle sized heater in the Mr. Buddy Portable Heater series and it has two settings, 4000 and 9000 btu. For most vandwellers this is the perfect size because the lower heat is more suited to the small size of our vans. On low (4000 btu) I’ve found it quickly warms up a van to being very warm and will soon need to be turned off. Of course the colder it is outside and the less insulation the van has, the more you’ll be glad you have this size. At normal winter temperatures, many people have found that leaving just the pilot light on overnight keeps the van warm enough to be comfortable with adequate bedding. Get it from Amazon here: Mr. Heater Buddy 4,000-9,000-BTU Indoor-Safe Radiant Heater

Mr. Heater Little Buddy Portable Heater: This is the smallest of the three sizes and I personally think it is the best choice for people in cars, SUVs, mini-vans and even vans because it takes up less space and has the lowest heat output at 3800 btu. Most people find that to be plenty and that the middle size Buddy puts out too much heat for the tiny space of cars and vans. With the lower output of this smallest heater, you can turn it on and leave it on with less time spent fussing with it. I had the middle sized Mr. Heater Buddy but I sold it and bought this one and I prefer it. Its major drawback is it’s difficult to convert to refillable propane bottles, but in a future post I’ll show you how. Get it from Amazon here: Mr. Heater 3800 BTU Portable Heater

Olympian Catalytic Heater, Wave 3: When I lived in a box van in Alaska for 6 years I used Olympian heaters as my only source of heat and I must tell you I consider them to be superior in nearly every way to the Mr. Heater Buddy heaters. They are a true catalytic heater while the Buddy heaters are not, so that makes them inherently safer, although the Buddy heaters are perfectly safe. They also have a 1500 btu setting, which is a much better size for most cars and vans because it provides a steady heat and burns less fuel. The only bad thing about them is they cost quite a bit more to buy and are slightly more complicated to install (they need a standard regulator on the refillable, bulk propane bottle). They make a larger Wave 6 and Wave 8 but you only need them in extremely cold areas, which most of us won’t be in.

The Olympian Heater Wave 3. It's a true catalytic heater so it is safer than the Mr Heater Buddy series and it's low setting is 1500 btu which is better for a van or car. I wouldn't hesitate to leave one on while I was sleeping.

The Olympian Heater Wave 3. It’s a true catalytic heater so it is safer than the Mr Heater Buddy series and it’s low setting is 1500 btu which is better for a van or car. I wouldn’t hesitate to leave one on while I was sleeping.

 Which one is Best for me?

There are no bad choices here, they are all great heaters! My advice is to buy based on 1) the size of your vehicle, 2) whether you might go to a bigger vehicle and 3) the severity of your winters:

  • For most people in a van in average cold areas, either the Mr. Heater Buddy Portable Heater (4000-9000 btu) or the Mr. Heater Little Buddy Portable Heater (3800 btu) is the best choice. You don’t need to run them overnight and they can be converted to run off bulk bottles easily. They’re cheap to buy and cheap and easy to run.
  • If you are in an RV then I recommend the Mr. Heater Big Buddy Portable Heater (4000-9000-18000 btu). You are going to appreciate the extra heat and the nicer features like a quick disconnect and built-in fan. Being portable you can have them in the living area during the day and in the sleeping area in the evening.
  • If you are a person who runs cold or live in a very cold area, then I’d recommend the Olympian Wave series of heaters. They can safely be left on over-night giving you steady heat throughout the whole day. In Alaska I would turn mine on in October and it would run 24 hours a day, 7 days a week until spring came, usually in May. I remember how wonderful it felt to finally be able to turn it off and know summer was near!! The Wave 3 should be warm enough unless you are in a very cold area. Then you may need the Wave 6 or Wave 8.
This is the simplist methd of conneting the Little Buddy to a 20 pound tank, just hang it from the ceiling by a bungee cord, screw in a filter, and connect that to the 20 pound tank. It can't fall over and is above where your dogs move around. Just be careful to check all the areas around it to be sure they don't get to hot.

This is the simplest method of connecting the Little Buddy to a 20 pound tank, just hang it from the ceiling between the seats by a bungee cord, screw in a filter, and connect that to the 20 pound tank. It can’t fall over and is above where your dogs move around. Just be careful to touch all the areas around it to be sure they don’t get too hot.

In my next post on heaters, we’ll talk about how to convert them to work off refillable propane bottles so you can save a lot of money on heat.

I’m making Videos with my good friends James and Kyndal on their YouTube Channel. See them here:



I have a series of videos comparing all these heaters. If you can’t see the heater video below, cut and paste this link into your browser:


Thanks for supporting this site by using these links to Amazon. I’ll make a small percentage on your purchase and it won’t cost you anything, even if you buy something different.


Mr. Heater Big Buddy (4000-9000-18000): Mr. Heater, BIG Buddy Portable Propane Heater

Mr. Heater Buddy (4000-9000): Mr. Heater Buddy 4,000-9,000-BTU Indoor-Safe Radiant Heater

Mr. Heater Little Buddy (3800): Mr. Heater 3800 BTU Portable Heater

My Buddy Filter: Mr. Heater Fuel Filter

Olympian Wave 3: Camco Olympian Wave-3 3000 BTU Catalytic Heater

Marine Grade Carbon Monoxide/Propane alarm here: Marine Technologies Combination Carbon Monoxide/LP Gas Alarm


I've been a full-time VanDweller for 12 years and I love it. I hope to never live in a house again!

41 comments on “Heater Comparison; Mr Heater Buddy versus Olympian Catalytic Wave 3
  1. Avatar Rob says:

    The medium size is a lot of heat in the van, I’m looking forward to your write-up on hooking the the small one to a bulk source (unless the ‘hang it from a bungee’ is it?)
    Other than the first picture you didn’t talk about the Coleman catalytic heater, I’m curious as saving space (over the mid size) is big thing.


    • Bob Bob says:

      Rob, I don’t have enough experience with the Coleman to really comment on it. The’re good heaters and have been around for decades so you can safely buy one. I also believe that they may have been discontinued because neither Amazon or Walmart are carrying them.

      Yes, I’ll show you another way to use the smallest Buddy heater.

      • Avatar Calvin R says:

        I found a link to the BlackCat that I had on the Coleman site–but it has no “add to cart” link. They’re still selling a few parts for it, but not the heater. http://www.coleman.com/product/2000004165#.Vkjxh4S37tR

        • Bob Bob says:

          Calvin, I think they are gone. I’d guess they just couldn’t compete with the Buddy or Olympian heaters.

          • Avatar Drew says:

            I’ve had two Coleman Blackcats, and I thought they were great. But they both developed holes in the catalytic fabric, which made them dangerous to use. On my first Blackcat, the hole was on the edge, and when it failed, there was a flame shooting out of it, about 3 or 4 inches! On the second Blackcat, the fabric tore away from the piezo-electric lighter (which kind of looks like a big rivet). I spotted it before it became dangerous. My thought is this problem is endemic with the Blackcat and that’s why Coleman does not sell them any longer. I’m now using a Little Buddy and it works well. I liked that the Blackcats because they had two heat settings, while Little Buddy has only one, and it seems to me the the Little Buddy produces a lot more water vapor, which is a big deal if you winter camp on the coast in WA or OR! On the other hand, I feel the Little Buddy is much safer, and you know what? That is far more important than anything else!

          • Bob Bob says:

            Drew I agree with all your conclusions! I would add that the Buddy heater does have two settings, but it gets hotter not less heat.

  2. Avatar molonewolf says:

    Very good info. I agree on the Olympian heaters they are nice. I have been enjoying the videos all full of good info. Keep the good info coming it is a big help. Stay safe out there my friend.

  3. Avatar Howiet says:

    11/15/15 Sat watching the first real snow fall of the season all afternoon.
    Temp is 33* F and my mid size Buddy heater is maintaining 70* on the low setting in my old high top Coachman van and it isn’t insulated all that well.

  4. Avatar Walt says:

    Bob, in that post perhaps you could address how the biggest Mr. Buddy heater could be plumbed (or hard-wired, as it were) into an RV’s existing propane supply. I know this can be done with an Olympian Wave catalytic heater, but I’d like to figure out how to do the same thing with a Mr. Buddy heater. (I thought I saw somewhere that the hose connector is a different size or something along those lines.)

    I know most of your readers probably have vans and cars (or maybe a Class C), but I enjoy the information I get from your posts as well and would welcome any insight you can offer. I think such a heater would be much more efficient in an RV than the built-in furnace and would help conserve electricity/battery power while boondocking – if I could figure out how to get it connected to propane without having to drill additional holes.
    Walt recently posted…#194 – Let’s Play A Game Of Musical ChairsMy Profile

    • Bob Bob says:

      Walt, I’m sorry but I don’t know RV systems or the Big Buddy well enough to advise you. But if you join my forum and post this question there I’m sure you will get all the help you need. Go to my website and at the top are menu buttons, click the one that says forum and then join.

  5. Avatar Jeff Agueda says:

    Great timing on this Blog post as I would like to replace my noisy forced air heater in my truck camper. Thank you for the information I need to make a decision.

  6. Avatar Ming says:

    darn, I didn’t buy the smallest one because I could not figure out how to ‘safely’ convert it for use with a bulk bottle.

    I think the truck canopy is a tad small for these? I can’t figure out where I would put it when 2 people are inside. I may try to build a tent to fit over the back of the truck.

    How cold does it get at night where you camp for the winter?

    • Bob Bob says:

      Ming if the shell is metal, then I wouldn’t worry so much about clearances to it because the metal isn’t combustible. It’s really hard to guess how cold it will be. The last two years it never got under 40, but in the past I’ve seen it down into the teens and windy, so that was cold. I can’t guess what it will be like this year but with the El Nino I would guess it will be colder than average.

      • Avatar Ming says:

        40’s at night sounds like ideal weather! Realistically, I am looking at next winter for a trip south, so who knows what will happen with el nino by then.

        Unfortunately, it’s a fiberglass cap. It looks to have an inch of insulation on the roof, but that’s not enough to prevent condensation from 2 people and a dog breathing in there all night.

  7. Avatar Steve says:

    I have been thinking about and preparing my vehicle to maybe attend the RTR in January. If…..and that is a BIG if…..I can get my vehicle (2014 Ford Escape) to accommodate me with a fair amount of comfort, I will try it. I know that the nights can get pretty cold from what Bob says, so I was thinking about using the Little Buddy for a heat source. But what bothers me is the small space that it would be in. It would be very close to just about anything wherever it would be sitting. Even if hung it up in the air like Bob has his, would be risky because it would be very close to the roof head liner. So maybe to solve this particular element of preparing my vehicle I will have to use a good sleeping bag. I also have found that the hand warmers that sell at Wal-Marts, Amazon, etc work great. They last 18 hours. I just tear open the bags, and put a couple or 3 of them in my sleeping bag and it really keeps me warm. they last all night, and then some. Then in the morning I would plan on reaching up and starting the engine to heat up the car before I get completely out of my bag. I don’t know if this Escape thing is going to work. But I do want to be as safe as possible.

  8. Avatar Canine says:

    What is the wattage of the CO/LP gas Alarm?

  9. The Mr. Heater heaters have oxygen depletion sensors. (Maybe other brands do too, I don’t know.) They will keep the heaters from using up your oxygen. HOWEVER, they’re calibrated to work below 7,000 feet. I discovered this when I was having trouble lighting my Little Buddy and keeping it going while camped near Flagstaff. I found a video from Mr. Heater that clued me in. So I got creative and just used my stove to warm up the van.
    Al Christensen recently posted…What is a guy without a house doing at Ikea?My Profile

  10. Avatar speedgene says:

    I camp at 6800 foot all the time and up to over 9000 in Nevada so the Mr heaters will not work. The Olympian is rated for it and doesn’t give me any problems. Mr. Heater loses efficient above 4500 foot.

  11. Avatar Tim Grimmel says:

    Hi Bob,
    Thanks to your website and YouTube channel, I’m starting to convert a van to live in, so I can follow my dreams! Thank you! My question is this…I couldn’t find a reasonable deal on a cargo van in this area, but found a great deal on a Dodge conversion van. It’s the short wheel base. I plan to remove the interior paneling, and attach foam boards, then panel over them. I’ll put reflectix in the windows. I will be living in my home state of Maine for 1 full year in the van, while saving money to start my travel adventure. Given that Maine has some cold winters, what size Olympian Wave would you recommend? I was thinking the 6 might be good, given the small size of the van.

    • Bob Bob says:

      Tim, one porblem you might have is with clearances around them, they need quite a bit of room. I had both a Wave 3 and 8. I used the 3 at normal temperatures, the 8 as it got coler and both when below zero. If you can’t afford that, get the 6 or 8 alone.

  12. Avatar Ben says:

    Great post. I might get a “Little Buddy” for full timing out of my car/tent, or maybe even a “Portable Buddy” if I go with a larger tank and hose setup. If I stick to full timing long enough this time, I might get an old Aerostar or Astro van and spend a month converting it. The last time, I spent 2 years working on a 5-10 MPG big V8 Class B, only to spend 5 months on the road with it. Now I have a 24+ MPG 4cyl, 4 door hatchback with a roof rack & box, and soon to be hitch and rear cargo box. I’m sick of apartment life in some ways, so it’s time to throw my life into chaos again and hit the road!

  13. Avatar Larry says:

    Do you know if the Olympian wave heaters have an oxygen depletion sensor? If I use a wave-3 or a wave-6 how much room do I need to leave around them?

  14. Avatar Gail says:

    I have a Little Buddy for my conversion van and like it very much. Despite it having a tip-over sensor, I wasn’t very happy with the small base that came with the heater. Didn’t do much to stabilize the heater/bottle. I just picked up a small Christmas tree stand (a plastic one with three screws that adjust the space where the trunk goes) for about $8. Works like a charm as a much larger, deeper, more stable base for the heater. Be sure to check the propane tank will fit in the space for the trunk, I had to get the larger of the two stand sizes to make it work. (It is about 12″ at the widest part.)
    Thank you for all your posts and videos. I’ve learned a lot from you and all your video subjects.

  15. Avatar earthwool says:

    Irrespective of the home you live in and the type of heating unit, heat will always flow from warm to cold until it matches the coldest place in your home.

  16. Irrespective of the home you live in and the type of heating unit, heat will always flow from warm to cold until it matches the coldest place in your home.

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