I am hesitant to make any claims as to fire safety etc. beyond saying we had no problems.
It should be kept in mind also that I had this trailer around 1969 and it was only 5 years old at the time.
In a small trailer it is a good idea to allow a little ventilation even if the heater is in good shape and vents outside.
We had a house furnace failure in zero weather and all 3 of us went to the trailer to keep warm ( the 14 ft with the floor furnace) It was a windless night and the trailer was buttoned up tight. In the morning we all felt bad, especially my 9 year old daughter.
Suspecting carbon monoxide, we went to the Dr. He told us that what had happened is we were suffering from the affects of Carbon Dioxide as we had essentially used up the oxygen in the trailer. Probably would not have happened if we had a window cracked or even if the wind had been blowing that night. Apparently a combination of the still night and 3 people in a very small trailer.
Anyway, just a word of caution for whatever it is worth.
Rick Davis 1602 K8DOC
61 tradewind, plus a few others
13 Ram 2500 TD
99 Dodge TD 577K miles