I agree with Defjef about the steam more likely being from water
. You might have water
in your fuel or be drawing low in a diesel tank where the water will collect. I am not sure I agree that unburned fuel would be white--it would be black or bluish smoke.
Another issue with these diesel heaters is that you need a lot of battery
to get some of them started. They draw 10 or 11 amps for the glow plug and this will draw down your voltage on a weak set of batteries to the point that some units will automatically shut down, or the glow plug will not properly light the combustion chamber and it will limp along at low heat and not get the condensate out of the system. You might try starting the heater with the engine
running (to get the additional amperage support of the alternator) to see if you get a better start. I am also told by some repair folks that many of these heaters are designed for European market where their diesel is more highly refined and that US fuel causes incomplete combustion from dirt in the fuel injection lines. It is possible that you have water in the exhaust
system and the unit is not getting hot enough to burn it off.
I have an old Wallas unit that I have come to love, having first become so familiar with it from disassembling it that I can do it blindfolded in about 10 minutes. From what I have gathered, all these units require maintenance
, but they can really extend the season and comfort for those of us in chilly areas.