TOPIC: Mobile home furnace rust

Hi Hippies,

Anyone else noticed that coleman furnaces in a manufactured homes seem to all have rust? Whats the defect causing it?
Condensation? lack of exhaust air flow?

Judging from the water stains I would say it is a roof leak. All the rusted ones that I find are leaks at the metal flange/roof covering intersection or flange/ven pipe seal. The older models with a low arc roof, the wind makes the metal roof pop and bang as does the expansion and contraction. These furnaces are always directly below the thimble and any leak drops right on it.

I have to agree with Ralph. I see many of these too and they appear to coincide with an updated roof. I usually find significant water damage along the (usually nearby) ventilation stacks.