Arctic Fox 990 question

Thank you for the great responses. The suggestion to go to the thermostat gave me a "Duh" moment for sure.:S Will have another look at things tonight. If I can control the furnace a simple switch install for the fan and we are good to go.

Wes the ventilation fan is not ducted however I have not seen any evidence of condensation as of yet nor have I heard of this being an issue. It's bone dry under there whenever I look. We have 10,000 k on it and over fifty nights so far. Have not had it out for winter camping yet but will definitely keep an eye out thanks for the heads up.

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I know folks love their Artic Foxes, but such a basement fan strikes me as a possible design flaw.

Apparently the fan draws warm, moist air from the camper cabin and circulates this water vapor laden air into the entire(?) basement cavity to provide some heat and prevent tanks from freezing. The guaranteed result of that method is copius condensation forming on any quiet, cool surface areas, in said basement, in keeping with typical basement heat loss. Areas such as wood tub structure (if AF uses that type construction) and stored metalic items will form a wet water droplets from essentially dry vapor causing some damage.

On the other hand, if the fan merely circulates continuous warmed cabin air through a sealed, non-insulated metal underfloor duct that merely radiates to the basement structures, no damage is done. Please tell me this is the case. Other than this possible flaw, I have always admired the well-known Arctic Fox extensive cold weather design. Some of my favorite camping was done in a TC in cold weather (-15F), although the camper was of marginal cold weather design.

Wes
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You might want to go back to the thermostat and nudge it to the off position just a little bit more. There is an ''all off'' ALL the way to the left, after it clicks. Then if you move 1 little millimeter to the right it clicks to the lowest setting about 50 and the basement fan will run 24/7. There is definanitly a click in between these two positions.

My 2005 990 thermostat has a disconnect switch that is opened when the temp is set all the way to the left (I think that removes ground from the furnace). My fan runs anytime the furnace (thermostat) is on, even when the furnace blower is off (keeps the air circulating). My fan is tied into the furnace wiring under the front dinette seat.

Until you have time to take a look you can pull the fuse to the furnace.

Good Luck,

The ventilation fan that you are referring to should only come on when the furnace runs. Its wired into the furnace circuit.
If your thermostat is shut off or all the way to the left, your furnace should not be running or trying to kick on. You might have a thermostat problem.

How about tripping the circuit breakers and/or pulling the fuses involved until you kill the fan & furnace? I'm not at my AF 990 right now and can't remember which is controlled by what, but there ought to be a way...