Propex Heatsource Furnace in pop up camper.

[ski3pin]

I'm still researching a possible furnace change in our All Terrain Camper. Julie and I spend a great deal of time in our camper and are looking to fine tune our heating a bit - if the improvement is really worth the effort, cost, and time.

I've done a lot of research on the diesel heater and for various reasons, I'm not interested in that direction.

The recent post on the Truma Varioheat piqued my interest. After initial excitement, I'm feeling it might be a bit overkill for our tiny camper. There's also an issue with size of the unit in planning an install.

There have been many posts in the past on Propex installs. I'm curious on opinions after long time use and in various environments.

I also notice that Propex is now offering a high elevation model for above 7500 feet. How has the standard version worked at varying elevations?

There is also the issue with running the long burner exhaust and inlet tubes.

Your insights, experience, comments are appreciated.

 

[Vic Harder]

Hey Monte. I put in Propex heaters in both my Hawk build and in the present Puma build. The Hawk had a 2200 in it, the Puma a 2600. The 2600 is "too big" for our camper... as in, the heat output is not ideal and the unit cycles too much, so the 2200 would be perfect. And we spent quite a bit of time at 15-20*F this trip, the furnace is still oversized.

I ran the long hoses outside the camper, one going forwards, the other back.

The furnaces themselves are rock solid reliable. Many nights over 7500' (is that supposed to be high?) with no issues.

I would not call the furnace quiet. Compared to my Indel-B based fridge, it is very loud! I could take Decibel readings if that would help. I've never had an Atwood furnace to compare it to though. The furnace has a multi-stage lighting process, and I can hear all of it when lying in bed. Slight relay click from the thermostat (which is right by my head - BTW we keep it at 44* at night, 62* during the day), the fan kicks in for about 20 seconds and then there is another relay click from the furnace itself as the gas turns on and the volume goes up considerably. How much? Um, on the outside of the camper you can barely hear the fan running. When the furnace comes on it sounds like any other RV.

Note: Our furnace is not mounted in a cabinet, but hangs under the cabinets in the foot kick-area by the sink. So, no noise insulation at all by being in a cabinet or having the hot air rush through a hose for some distance. YMMV.

Would I get another? Possibly, but the 2200 model for a Grandby/Puma. I would be very curious to know why you are not pursuing the diesel heater option ... I've considered the TRUMA and got really excited when I saw that they have a diesel option, but only for the COMBI which is actually quite a large box. When I was chatting with Stan during his excellent guidance through their factory in February, he said FWC could not get the COMBI to fit, so they actually use the separate heater and water heater... (thus not really saving any space??? ) If the smaller Truma heater came in a diesel option, I'd be very tempted.

Then there is the "only Truma authorized" dealers can install the unit conundrum. There are not many out there. And what might service be like? Dunno. Service from Propex has been exemplary (I asked a few questions during install, and managed to blow an internal fuse... both times I got responses to emails within 24 hours).

 

[ski3pin]

Vic, thank you for the detailed response.

I've dropped the idea of a diesel heater because I'd need to install a fuel tank to feed it. Also, I'm concerned about the issues I've read about sooting and operating at elevation.

I have an Atwood and it has been, pretty much, maintenance free and it works. It is just too big - as you describe. It heats fast but rises the temperature in the camper well above the set point. Then the camper needs to really cool down before it comes on again. Hot then cold. Hot then cold. We'd like a more steady temperature.

Installation wise, I can easily make the Propex fix where the Atwood is installed. The Truma would require moving up into the main cabinet. The Truma I could install with the exhaust (and intake) right in the side of the camper unlike the long tubes of the Propex.

There is one person on ebay selling the Truma heater and install kits. Warranty and service issues could be a real problem. I've not made inquiries.

We are both about done with the Wave 3. It is in the way. It pumps moisture into the camper. Even with venting, our eyes will start to be irritated after a couple of hours running it. We do love the more even heat.

It is a lot to contemplate.

 

[goinoregon]

i installed the propex hs2000 in my atc, and it worked great, and in my opinion, was pretty quiet.
i exhausted thru the door atc put in for a propane tank in my shell, but i never set the shell up to put propane in the cabin.
my solution at the time was to hang a tank off the back lift brkt, and then use a quick connect hose to pass the gas from outside to in.

only used a few times, but was happy with the heating. the unit construction seems to be very good.

let us know what direction u go.
greg

 

[Vic Harder]

Monte, have you seen where I mounted the heater in the Puma? It takes up NO room (at least none that was going to be used by anything else).

Also, the heat cycling issue seems to be thermostat and oversize related... as in, too much hysteresis in the thermostat and too much power in the heater. If the heater was undersized, it would come on and run continuously.... = no heat swings.

The long tubes are a small issue for us only when loading and unloading, as it makes it even tighter at the sidewalls.

 

[ski3pin]

Vic, yes I looked at your installation prior to posting. I am curious how others here have routed the long intake and exhaust tubes.

I agree with what you say about heater size and thermostat. This is why I would go with the small HS2000.

I also see that Propex is now listing this new heater on their website with variable speeds similar to the Truma Varioheat -

Whale Heat Air GTR10

 

[Taku]

have had two Propex furnaces - first in ATC Ocelot and second in ATC Cougar. both pretty bombproof although the first did need a switch replaced at RV dealer for about $350.00 - that's when I found out they recommend starting the heater up monthly which I had not done over the winter. Have used them in 0 temps and at 9500' in the Beartooths with no issues. Are they loud? I guess yes and no. in our Cougar the furnace in a 1/2" plywood box with no insulation and it doesn't wake us up at night. We do only run it at about 45 degrees so doesn't run often. Long hoses - not a problem with either camper or vehicle (both Tundras). Inlet hose is attached to the plywood camper bottom and it fits fine, the exhaust hose goes through a hole drilled in the bed so exhaust gases have no way of being sucked into the inlet hose. Just need to remember to slip the hose back up when you take the camper off. Diesel heaters have some advantage, the heaters that tap into your gas tank have advantages, and the Propex has advantages. For me having done two builds the ease of installing the Propex and the reliability win out. Oh, also the newer Propex has the digital thermometer which is way nicer. If you do need to take it out for whatever reason, it may not be as easy as some furnaces, but depending on how complex and install you do, it is not bad. But have had to take one out only once so far. Let me know if you want to see some pics - I can do that.

 

[ski3pin]

have had two Propex furnaces - first in ATC Ocelot and second in ATC Cougar. both pretty bombproof although the first did need a switch replaced at RV dealer for about $350.00 - that's when I found out they recommend starting the heater up monthly which I had not done over the winter. Have used them in 0 temps and at 9500' in the Beartooths with no issues. Are they loud? I guess yes and no. in our Cougar the furnace in a 1/2" plywood box with no insulation and it doesn't wake us up at night. We do only run it at about 45 degrees so doesn't run often. Long hoses - not a problem with either camper or vehicle (both Tundras). Inlet hose is attached to the plywood camper bottom and it fits fine, the exhaust hose goes through a hole drilled in the bed so exhaust gases have no way of being sucked into the inlet hose. Just need to remember to slip the hose back up when you take the camper off. Diesel heaters have some advantage, the heaters that tap into your gas tank have advantages, and the Propex has advantages. For me having done two builds the ease of installing the Propex and the reliability win out. Oh, also the newer Propex has the digital thermometer which is way nicer. If you do need to take it out for whatever reason, it may not be as easy as some furnaces, but depending on how complex and install you do, it is not bad. But have had to take one out only once so far. Let me know if you want to see some pics - I can do that.

Taku, thanks for the response. I appreciate your insight and experience. Yes, a few photos would help very much as I run possible designs through my head.

 

[ski3pin]

As an aside to this. In my research I found an old Truck Camper Magazine article that said the Four Wheel Campers that were built for export to Europe had Propex heaters installed.

 

[Taku]

Hi Ski: cannot get the photos uploaded here. let me know if someplace else works. I like the looks of the Whale Heat - that might be an interesting option. With your small camper, it might be overkill.

 

[ski3pin]

Taku, here's a little help with your photos. Thanks for your comments!

plywood box housing the propex

exhaust tube exit in truck bed, photo from below

 

[Vic Harder]

I like that Whale as well… have to look into that one a bit more.

 

[Taku]

yes, looking at the Whale, it appears that the bracket allows mounting in different positions. that would help for different configurations. I wonder how long the air inlet can be? Appears to be pretty short, so that might limit some areas for mounting. A bit bigger than the Propex, but not out of the question. Hope someone here does get one and reports out!

 

[ski3pin]

Yes, the Whale Heat Air has some wonderful features that makes it very attractive. Unfortunately, as I look at possible installation scenarios, the length with heat and air intakes at opposite ends makes it difficult.

 

[Defulmmt]

After 9 months of troubleshooting the Dometic and replacing the sail switch it has operated without fault for 18 months. The problem I experience in use is the constant cycling on/off and warm to cold.

I have been researching options to the Dometic installed in my Panther. Diesel is a nonstarter for me because I have a truck with a gas engine and don’t want to handle fuel for a separate diesel tank. After reading the installation manual for the Truma and lacking access to an experienced dealer who could perform the install I am leaning to a Propex.

The Propex combustion and exhaust tubes do have me a bit concerned. Van Cafe sells a through the hull vent and their website lists it as in stock. https://vancafe.com/2986120-propex-22mm-marine-thru-hull-fitting/

I think that I could use the existing plate that the Dometic vents through, (on the Panther this in the lower left rear of the camper) and modify to use this vent. The Propex installation instructions, however, state that the two vent tubes should be separated by .5 meters. Any thoughts on the safety of this approach would be appreciated vis a vis CO contamination of the combustion air vent. It seems similar in principle to the concentric vent that the Dometic uses.

 

[ski3pin]

<snip>

I also notice that Propex is now offering a high elevation model for above 7500 feet. How has the standard version worked at varying elevations?

<snip>

Actually, more correct is that vancafe is offering a modified propex for use above 7500 feet. I talked with the tech who explained the unit works fine at sea level but the modification improves the burn at elevation.

 

[ski3pin]

The project that grows arms and legs. They seem to always grow arms and legs.

I put a lot of thought this past weekend into a possible furnace swap. I want to do it right the first time.


I want to use the space currently occupied by the Atwood Hydroflame.

The easiest installation would be mounting on the floor and drilling down through the floor pack for the combustion exhaust and intake tubes and running the tubes externally in the area between the camper bottom and bumper.

But tolerances are very close and the exhaust port may not clear the truck bed.

Or I could mount the propex furnace higher, loop the exhaust and inlet air tubes in the space below the propex furnace and exit them via a thru hull fixture. That would allow keeping everything internal to the camper.

Defulmmnt, I also am confused by the conflicting information about the required distance between the exhaust and inlet exit points. The instructions state .5 meter. But they sell a thru hull and also an exterior bracket where the the exit points are right next to each other. Also, other furnaces, such as the Atwood, Suburban, Truma, have the exhaust and inlet right next to each other.



In regard to running the exhaust and inlet combustion tubes interior to the camper, look at how Four Wheel Camper company does/did it in their European model campers with the Propex.

In the above video, the propex is visible at 2:27 to 3:15. The tubes exit the camper with a thru hull in the drivers side that it visible later in the video. It is branded "propex". And yes, this is ironic because they are removing the Propex and replacing it with an externally mounted diesel heater.

Growing arms and legs. I want to redo the exterior back to the aluminum siding after the old Atwood furnace cover and furnace are removed.

The current "furnace box" at the lower rear corner of the camper is 17.25" long by 10" wide and 17.5" high. I could, possibly increase the width up to 12". BUT, if i got Marty to work with me, we could redo the floor pack and increase the length by 9" (new 26" length) and go to bolt through camper mounting in the rear and eliminate turnbuckles. Yup, arm and legs.

But the thought keeps reoccuring to me, if I put in this work, should I go to a more advanced furnace like the Whale Heatair or the Truma Varioheat?

A lot to contemplate........

 

[goinoregon]

since u use your camper in the cool months, i figure some thinking on it is ok. that said, u have managed for a lot of miles, with the stock atc version heater.

 

[Defulmmt]

I contacted VanCafe tech support and asked them to advise regarding the through the hull vent. Their reply:

“ Here the included instructions with the Marine Thru-Hull fitting. As you can see it's a curious product that we don't recommend for many installations. We aren't a fan of modifying the exhaust and intake pipes in any way even though Propex states modification is possible, we don't recommend it.”

As you said there is a lot to contemplate.

 

[ski3pin]

I'm considering this stainless steel thru hull - 22mm stainless thru hull -
much cheaper and with straight pipe.