Display shows E6 and the outdoor unit may not respond; intermittent cooling with communication loss.

Safety first: Shut off power to both indoor and outdoor units at breakers and disconnects.

• Step 1 – Verify wiring diagram: Locate the Keeprite wiring diagram on the service panel. Confirm that each communication terminal (e.g., C, R, Y, Y2, Data) is wired to the matching terminal at the other end using the same color wire.
• Step 2 – Inspect cable: Follow the low-voltage cable along its route. Look for staples through the jacket, rodent damage, or UV-cracked insulation. Replace damaged cable with thermostat wire of equal or larger gauge.
• Step 3 – Tighten connections: At both control boards, remove and reinsert each low-voltage wire, tightening terminal screws securely.
• Step 4 – Grounding check: Ensure the outdoor unit is properly grounded and that the ground wire is intact at the disconnect and panel. Poor grounding can cause communication errors.
• Step 5 – Restore power and test: Turn power back on and command cooling. If E6 persists, the outdoor control board or indoor board may be defective and should be tested/replaced by a technician.