Furrion E3 fault code — Rooftop air conditioner
Applies to: Furrion rooftop air conditioner with wall thermostat/control box
What E3 means
The Furrion rooftop air conditioner manual lists E3 as loss of communication between the thermostat and control box; system will shut down.
Owner-safe checks
- Turn HVAC mode off if the unit is not responding.
- Record the thermostat model, control-box model, and whether the system shut down.
Service-only work
- Sensor, communication wiring, control box, rooftop HVAC, and low-voltage diagnostics should be performed by qualified service personnel.
Safety boundary
Disconnect power before HVAC service. Do not open rooftop or electrical compartments unless qualified.