My friend Mike purchased Humpty Dumpty from me. This is a 1973
Trillium 1300. The
furnace in this age range is different from the 65810-002 in later model 1300s. I have a spare
furnace for this trailer, so I figured I would do a tear down of it.
First off, it has the same gas valve as the other Duo-Therm furnaces in Trilliums. The
ITT RV18AA. The following pictures are from the tear down.
It is not supper obvious, but there is some fancy duct work on square outer housing. The exhaust pipe is surounded by the combustion air inlet. At the fire box end of the exhaust pipe, where the gasket and it's holder can be seen, there is a space, between the two layers of metal, that ducts the incomming air to the bottom of the combustion chamber/heat exchanger. Inside the combustion chamber, just below the exhaust pipe, is a baffle that slows the flow out of the exhaust. I assume this is to keep the hot gasses in the heat exchanger longer so more heat is transfered to the inside of the trailer.