Which heater is best: Forced air, ceramic or catalytic?

By Greg Illes
We were up on the North Rim of the Grand Canyon, boondocking out in the Kaibab Forest at around 8,500 feet elevation. It was October, and the nights were regularly dropping into the 30s (F).

cold forestOur stock cabin heater, a standard Suburban 30,000 BTU fan-driven beast, had long since been sidelined in favor of a small propane heater. Oh, we still used the “big heater” for warming up the coach in the morning or after long absences. But the “little heater” was very nice at maintaining the cabin temperature. At first we used a Mr. Heater, but later moved up to a 10,000 BTU free-standing unit. It was made with two ceramic panels that glowed red-hot at full tilt. Even later, we mounted that heater on a cabinet.

But that chilly October night, the little auxiliary heater simply would not stay lit. Not even its pilot would stay lit, sputtering and flickering and dying until we finally gave up. We spent that night listening to the noisy fan go on and off, and thinking about all the wasted propane being blown out the side exhaust (used to vent combustion gases).

After the trip, I did some research on these ubiquitous ceramic heaters. I discovered that the design of these units has an inherent limitation, and that they simply cannot be relied upon to operate anywhere above 4,500 feet elevation. It’s a little complicated and slightly technical, but stay with me here …

Essentially, the safety-oriented ceramic-heater design will not allow the heater to function when oxygen levels drop – as they do with rising elevation. Normally, the combustion process produces carbon dioxide (CO2). But at low oxygen levels, in a “burner” style design, reduced oxygen causes the creation of carbon monoxide (CO), a deadly gas. Not good.

The “blue flame,” or open-flame, heaters are a different variation on the ceramic style, but their combustion technique also limits them to 4,500 feet or less. The specs vary slightly among manufacturers – if you can find the specs at all, that is. Calls to manufacturers about altitude were often met by dumb silence.

More research revealed that only one type of heater would work at high altitudes – the catalytic type. Catalytic heaters don’t actually burn propane, they catalyze it. The consequence of this is that there is NO possibility of catalytic heaters generating CO. As a result, their design does not require oxygen sensors, and they will operate independently of oxygen density.

CERAMIC vs. CATALYTIC vs. OPEN-FLAME vs. FORCED-AIR

At that point, I thought I had it knocked. Just buy a different heater, one with a catalytic design.

Then I found out that true catalytic heaters – suitable for RV use – were:

  • Made by only one manufacturer – Camco “Wave” series
  • Cost almost 3X as much as higher-power ceramic/flame heaters

Ouch. No competition, captive market.

But, oh well. Out here in the mountainous West, less-than-4,500-feet excludes thousands of square miles of great space to explore. So I bit the bullet and bought a Wave-8.

Fabulous! It worked anywhere, at any altitude, giving off copious silent heat at nearly 100% efficiency. I mounted it on a swivel panel on that same cabinet, so we could direct the heat where we wished. Opening a window slightly to provide oxygen and vent water vapor, we were truly happy campers …

Until about two years later, after maybe 6-8 months of actual use. Then it started getting temperamental and going out. Within a few nights, it quit completely. Ugh. Back to Mr. Noisy again.

Back home, I called up Camco and talked to a Wave technician. Had I been scrupulous about keeping the catalytic screen covered when not in use? Yes. Had I spilled or sprayed anything against it? No. Was I giving it good propane? Yes. From west of the Mississippi?

HUH – WHAT?

Yeah, I heard him right – it turns out the propane in the Western states is contaminated (intentionally) with a lubricant that eventually ruins the catalyst in the Wave catalytic heaters. No mention of this whatsoever in the product literature (of course). And nothing that can be done about it either, according to the tech. They are “working on it.”

I’m now faced with a crummy choice – buy a cheap ceramic heater that will last indefinitely but won’t work at altitude, or buy an expensive catalytic heater that has to be replaced every few years. (Actually, only the catalytic element has to be replaced, but the cost is nearly the same as a new heater.)

Well, I really hate that noisy forced-air heater, and I’m not going to be camping exclusively at low elevation – so I’m stuck with the short-life catalytic for now. Maybe somebody at Wave will figure it out? I won’t hold my breath.

So here’s a quick summary of my multiple years of experimentation:

20180713_135527FORCED-AIR

  • Standard on virtually all RVs, thermostatically controlled
  • Big, heavy, expensive (but built-in and well-hidden)
  • Heats the cabin very quickly, much faster than portables
  • Noisy
  • Battery hog (8-10A) – can drain batteries overnight
  • Propane hog – 70% efficiency at best, much heat is exhausted outside RV

 

20180713_135913CERAMIC or BLUE-FLAME

  • Inexpensive substitute for forced-air heater
  • Available with thermostat
  • Uses NO battery current
  • Nearly 100% efficient
  • Generally long-lasting and trouble-free
  • Available in portable and wall-mount
  • Intermittent or non-op at >4,500-feet elevation
  • Can produce carbon monoxide

 

20180713_135648CATALYTIC

  • Much more expensive substitute for forced-air heater
  • Thermostat not available
  • Uses NO battery current
  • Nearly 100% efficient
  • Operational to 12,000 feet elevation
  • Cannot produce carbon monoxide
  • Must be covered when not in use, susceptible to dust/dirt/spills
  • Configurable to free-standing or wall-mount
  • Fuel contamination (western states) requires periodic replacement

As you can see, the choice is not always clear, or easy. But I hope this rundown helps you shortcut your learning curve, and/or maybe explain some mysteries you’ve yet unsolved. Good luck staying warm.

Greg Illes is a retired systems engineer who loves thinking up RV upgrades and modifications. When he’s not working on his motorhome, he’s traveling in it. You can follow his excellent blog at www.divver-city.com/blog

##RVT854

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18 Thoughts to “Which heater is best: Forced air, ceramic or catalytic?”

  1. Brian Reed

    I’ve been using a Buddy Heater and Big Buddy since shortly after they came out around 2000. They have been used extensively in the Ca Sierras and the Rocky Mts at elevation of 8,000’-11,000’ over the years. I’ve heard of the altitude issue from other people and the instructions do state for use under 5,000’. I have never had an issue but it is critical to keep the ceramic element as lint and dust free as possible during non use. I have replace the Buddy ceramic element once the the primary element on the Big Buddy once each.

  2. John T

    I’m skeptical about this lubricant claim. I searched out some HD-5 propane specs online, including the California state spec, and there is no mention anywhere of a lubricant.

  3. A Pseudonym

    Good day, Mr. Illes.

    We full-time at 9000’± in Colorado, and use a Dyna-Glo Construction Heater. No problems thus far (1 season) other than the tip-over sensor failed. (It was replaced at $0 cost by Dyna-Glo.) We, too, leave a window partially open for venting.

    Regards,

    Michael

  4. Wolfe

    I haven’t found any reference to intentional lubricant in LP, but it sounds like a simple gas filter would catch whatever contaminants are the issue. Depending how much contaminant there is, it could be done with a disposable inline filter or an empty-able “dryer” type filter cup.

    There IS often contamination (dirt, excess odorizer, etc) in LP, which it’s why there’s always a drip tee or filter on home appliances – not sure why RVs wouldn’t follow the same need.

  5. Gene Bjerke

    We bought a Mr. Heater Buddy, a small, ceramic heater. It produces enough heat for our Class B, and is quiet, etc. We liked it —but— it uses a one-pound bottle that only lasts for five hours on the low setting. Not enough for heat all night. Theoretically, we could have it plumbed into the coach’s propane system, but I was unwilling to make that (probably expensive) move; we don’t spend a lot of time in real cold weather.

  6. Rudy Globokar

    About 20 years ago I bought a Martin ceramic heater at the market in Yuma, AZ. I didn’t have any trouble with it until I tried using it in the mountains here in Utah. It would not stay lit. I called Martin and they told me it was designed to operate efficiently at sea level and was told to open a window. It still wouldn’t stay lit.
    I had it tapped into my gas line inside the trailer with a long hose so I could move it around.
    One day I did a stupid thing to try to use it in my garage with a portable tank without a regulator and ruptured the diaphragm.
    I took it to a local repair shop and was told that they could repair it and tweak the air supply as they had done for some heaters at a local ski resort at 9000 feet. They did the repair and I have not had a problem at any elevation since.

  7. Jake

    WHAT ..a great piece and thanks to all that have commented ..RV’ers are special people and I am so glad to be part of this traveling brothers & sisters since Dec.1977 when the wife and two young daughters bought our first RV trailer and hooked to our quiet new Lincoln Continental 4 dr and headed to Florida west coast for Christmas from Maryland with the girls as I was already into my Naval Air career 15 years and it was a near disaster adventure as our first short trip recommendation was ignored and not smart for sure..But thanks to the RV people along the way ..we are still traveling RV’ers and will never quit until can’t drive anymore..USN{ ret.} 30 years..The heating info was outstanding ..Thanks

  8. Loren Robinson

    We too have been using an Olympian Wave 6 since 2000, mostly in the west with no problems. We do keep it covered when not in use.

  9. Gregory Illes

    I’m sorry, but I can’t provide any more information on the contamination issue. I was given this information by a technician at Wave, and I have not pursued it any further. If anybody is curious please feel free to call Wave for more information.
    And for certain, if Wave has solved this issue I would be very happy to hear about it.

  10. Ray Morgan

    I also have a Wave 6 that is 8 years old and has hundreds of hours of use from sea level to over 8500 ft. 95% of the propane we buy is in the west. We’ve never had a problem.

  11. Fred P Burns

    There are thousands of us using the Camco Wave heater. We need clarification on why the Western states contaminate propane with a lubricant.

  12. Seann

    On the Waves is it not possible to just replace the catalytic panel?

    1. Fred P Burns

      My understanding has been that the factory will not send you the mat material for self replacement. They insist on replacing it at the factory, probably for liability reasons.

  13. Cyndie

    We lived on the South Rim of Grand Canyon at 7,400 feet for 16 years. We have a blue flame wall mounted heater that has never given us a problem other than needing a new thermocoupler now and then. For about the last 8 years we were there, we also used a Mr. Heater Little Buddy. Never a problem with it also. These 2 were used in the shoulder seasons (spring and fall) to give us quiet heat. We had to use the noisy furnace in winter. We also used the blue flame heater at 8,500 feet in the Big Horn Mountains of Wyoming one summer (nights get cold even in summer there) without any problems. We always have at least one roof vent open.
    We would like to know more about this statement “propane in the Western states is contaminated (intentionally)”. Could you please elaborate?

  14. DXRFLYER

    Interesting that this article and others like it never mentioned that forced air heaters provide heat to isolated spots in the RV that would be subject to freezing during cold weather. Free-standing heaters do not provide this heat only heating the living area.

    1. Fred P Burns

      That’s why, when the temp is going to drop significantly below freezing, we run the forced air furnace shortly before going to bed & then again first thing in the morning to heat up the basement & water tank compartments, but use the Wave heater during the night for efficiency.

  15. Richard Heberlein

    Interesting comment about propane contamination in the west.
    We have owned and used a wave 6 since 2003 with no problems even without covering it and with plenty of western propane run through it. It was made by Olympian before Camco bought them. Don’t know if that made any difference but just say’in.

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