17B Propex Furnace Install

[BillDavis9663]

I ordered my 17B without furnace and air conditioner. Previous experience 20 years ago with a Rockwood pop up that had Coleman a/c on the roof and whatever furnace they were installing back then. Both heater and a/c were way oversized and so loud you could not hear yourself talk. Wasn't going to make the same mistake with my retirement trailer and opted to do my own installs. For the furnace I settled on the Propex HS2000 (6,500 btu) with a marine thru-hull install kit from Sure Marine Service out of Seattle WA. It fits with room to spare in the same space underneath the cooktop on the 17B where ETI installs. Combustion and exhaust tubes are 48" each and drop down into the bottom storage cabinet but doesn't take away any significant space. Combustion tube stays in the bottom cabinet and snakes around the plumbing and exits at the bottom near the wheel well. Exhaust tube is in a wide 270 degree arc that comes back up into the front of the furnace compartment and exits with the thru-hull fitting above and behind the furnace. Biggest install issue is ensuring there are no air flow restrictions in the tubes. Did a few calculations on the back of an envelope but to make sure I did a bench mockup that roughly matched the bends I was envisioning. It ran without issue or faults for an hour and I was satisfied enough to drill the exterior holes. Approximately 10" of expandable/flexible heater duct connects the furnace to the outlet which is mounted in the cabinet door. I did have to drill another hole in the furnace shelf to get my hand inside to make final duct connection with hose clamps. I opted for the simple 2 knob control for temperature control. They do offer a digital thermostat but I've been through one season with the 2 knob controller and so far I haven't seen the need for it.

[Ron in BC]

Good work. Nice well thought out installation.

Seems quite suitable for the use intended.

Ron

[Mike G]

Does that black vent in the door connect to the heater output opening? From the camera angle, the vent looks higher than the heater. Just wondering.


I like the specs on those heaters, and if my furnace ever failed I'd strongly consider replacing it with a Propex.

[rubicon327]

Glad to finally see a Propex furnace install documented. I know one other forum member that installed one but they never posted details. If our trusty Atwood 8012-II ever dies the HS2800 will be on the list. One recommendation is to make sure your return air path is not restricted. You might consider cutting a small grille in the face of the cabinet door under the supply outlet. Besides good return air if you design it to be easily removable you could have access to make your supply duct connection and maybe other adjustments.

[LtDan]

Nice work. I installed the same heater in our 17’ Casita several years ago and was very pleased with the quiet, efficient performance of this unit.

[dstreight]

Interesting to follow along on your build...considered the Propex originally for our 15A project but ended up in the Espar corner.

[Jim Bennett]

I installed one in a Trillium rebuild I did for my daughter about 7 years ago it works great. The only charge I would make now seeing how tough they are built would be to do the external unit mounted underneath and freeing up more interior space for them.

[BillDavis9663]

Originally Posted by Ron in BC

Good work. Nice well thought out installation.

Seems quite suitable for the use intended.

Ron

Thanks Ron. It was a fun engineering/install project. The only information I could find on the internet dealt with van conversions and boats. In sizing the smaller HS2000 I figured the interior space was about the same as a Sprinter van so it should work for the 17. Really happy with the result and performance. During the install I disassembled a lot of cabinet interiors for routing the controller cable loom to the opposite side of the trailer. In the process I got to know how the interior is stapled and screwed together and what's under the skin.

[BillDavis9663]

Originally Posted by Mike G

Does that black vent in the door connect to the heater output opening? From the camera angle, the vent looks higher than the heater. Just wondering.


I like the specs on those heaters, and if my furnace ever failed I'd strongly consider replacing it with a Propex.

Yes the vent is higher than the heater output by a couple of inches but flexible heater duct hose allows it to mate.

[BillDavis9663]

Originally Posted by rubicon327

Glad to finally see a Propex furnace install documented. I know one other forum member that installed one but they never posted details. If our trusty Atwood 8012-II ever dies the HS2800 will be on the list. One recommendation is to make sure your return air path is not restricted. You might consider cutting a small grille in the face of the cabinet door under the supply outlet. Besides good return air if you design it to be easily removable you could have access to make your supply duct connection and maybe other adjustments.

Thanks Rubicon. With all of the discussions around various heater problems and folks looking for an alternative I thought I could contribute my experience. The Propex 2000 or 2800 are definitely options that should be considered.

Return air is an interesting discussion and not much info available for the Propex. Most of the van installs I read about had no return air duct and just left it open in the space the furnace was installed. SMS provided excellent installation instructions and information. They state the inside, outside or a mixture can be used for the cold air intake. I decided to keep it all inside as I didn't want another hole in the exterior and I would lose too much storage space by dropping a duct hose into the lower cabinet. I got very used to the storage space inside the furnace cabinet during the time before installing heater. I had used the space to store 2 slide out plastic bins for cooking oils, liquids and spices. When I installed the furnace I had to resort to building shelves above the countertop to store those things. Not much storage in the 17 compared to other models and the bottom cabinet is the only place big enough to hold pots, pans and other heavy items so no way can I give that up.

The cabinet door is still functional in that it still opens and closes on the hinges I secured it to keep from opening (inquisitive minds and bucking down the road) with two screws top and bottom. Remove those and the disconnect the short piece of duct to the outlet and there is complete access. I contemplated putting in a duct from the cold air inlet to inside the wet bath which is directly adjacent to the furnace cabinet. I could still do that but found that up to now I haven't needed to.

Attached pic is from SMS installation and instructions on the cold air return.
Bill

[BillDavis9663]

Originally Posted by Jim Bennett

I installed one in a Trillium rebuild I did for my daughter about 7 years ago it works great. The only charge I would make now seeing how tough they are built would be to do the external unit mounted underneath and freeing up more interior space for them.

Jim, Ditto on the change but at the time that was a different animal I didn't want to take on. Just not enough info on the net for a fiberglass trailer install. The exterior installation allows for several location options and alleviates the very expensive thru hull fitting for the exhaust, snaking tubes in and out of cabinets as well as freeing up valuable interior cabinet space. Having one install under my belt and seeing how relatively easy it was I can definitely recommend looking at the exterior model as the better option. Bill.