Furrion E4 fault code — Thermostat
Applies to: FACW12ESPA-BL, FACC12ESPA-BL control box
What E4 means
The Furrion thermostat manual lists E4 as outdoor coil sensor out of order; 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.