Display shows E7 and unit may not operate in certain modes (cool, heat, or fan).

Safety first: Unplug the unit. High voltage is present on the control board and compressor circuits.

Steps to address E7:

• 1. Confirm model type: Check if your Koldfront unit is cool-only or heat/cool (heat pump or electric heat). E7 often relates to mode control on heat-capable models.
• 2. Try different modes: With power restored, attempt to run in fan-only, cool, and heat (if available). Note which modes trigger E7.
• 3. Inspect wiring: Disconnect power, remove the control box cover, and inspect wiring to the fan motor, reversing valve coil (if present), and any electric heater elements.
• 4. Check connectors: Reseat all multi-pin connectors on the main control board.
• 5. Listen for relay clicks: When switching modes, you should hear relays click on the control board. No click or repeated clicking with E7 may indicate a bad relay or board.
• 6. Professional diagnosis: Testing the reversing valve coil, fan motor windings, and heater circuits requires a multimeter and knowledge of the wiring diagram. Have a technician perform these checks and replace the faulty component or board.