RV Appliance Code Atlas

Dometic Single Zone LCD auto fan speed cycling

Dometic Single Zone LCD thermostat instructions say Auto fan varies by the difference between setpoint and room temperature: the fan runs HIGH when the difference is greater than 5 F, LOW when it is less than 4 F, and cycles with the thermostat.

Owner-safe checklist

  • Record selected mode, setpoint, room temperature, and whether Fan shows Lo, Hi, or Au.
  • Treat normal Auto fan speed changes as expected when room temperature approaches the setpoint.
  • Select Lo or Hi from normal fan controls only if continuous fan operation is desired.
  • Call qualified RV HVAC service if the display mode changes but fan behavior never matches the thermostat selection.

Official sources