I've bought in July a Trillium
65512 with a Duotherm 65512 heater that had been removed because the previous owner used the space for extra storage and preferred to use an electric heater. I prefer camping in national parks and in places and times where a heater is a necessity but electric power is usually not available.
I tought it was worth to try reinstalling the furnance. I soon found out the original gas line had been cut. So I installed a T under the floor and routed a new line along the outer edge of the frame all the way behind the right hand wheel. I installed a valve at the end, so I can cut the gas only on the heater in case of emergency or maintenance (considering the heater is 34 years old, I figure I may need to cut out gas on this line one day while maintaining fridge
and stove top operation).
I drilled a hole on the lowest point of the floor just next to the electric transformer and connected the new line (shaped to the final position) on the back of the heater and pushed it in position. The tricky part is really to turn the connector on the back instead of the side of the unit, so that the gas line does not have to be connected when the unit is already installed, by some elusive tool or trick I can't figure out, There is hardly any room to play with tools around the heater once inserted. Once connection seal tested OK with soapy water, I reinstalled the exterior exhaust/intake module and voilà ! It is working like a charm.
There are now a few small catalytic units available, which would only require a small fraction of the space and use much less gas and hardly any installation effort, but I just could not justify the few hundred dollars extra for as long as the old Duotherm furnace
worked so well, with the benefit of thermostat, silent operation and no need for a fan or any electric installation whatsoever.
I was very pleased to find a detailed intruction booklet applicable to my furnace
on this site, thanks.