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Maybe, it only makes sense to me? I did not want to call the RV repairman out in this near-freezing weather. I “played”  with the thermostat: “Off”  for a couple of minutes, then cycle to “furnace.”  Seventy degrees and no response. “Off”  for a couple of minutes. Seventy-two degrees and no response. Slowly, with increments, the temperature was raised to eighty-four and furnace clicked “on.” 

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Reasonable conclusion? The thermostat has ceased to function accurately?

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