Indoor unit shows E1 and the system will not start cooling or heating.

Safety first: Turn OFF power at the outdoor disconnect and main breaker before touching any wiring.

• Step 1 – Verify power and polarity: At the indoor and outdoor terminal blocks, confirm that Line (L) and Neutral (N) are correctly wired and match between units. Klimaire split systems are sensitive to reversed polarity.
• Step 2 – Inspect communication cable: Locate the multi-core cable (often 3–4 conductor) between indoor and outdoor units. Check for cuts, rodent damage, or crushed insulation. Tighten all terminal screws firmly.
• Step 3 – Check for mixed gauges or splices: Ensure the interconnecting cable is continuous and of the recommended gauge. Poor splices or mixed wire sizes can cause intermittent E1 errors.
• Step 4 – Power cycle both units: Turn OFF the breaker for 5–10 minutes, then restore power. Wait several minutes to see if the indoor and outdoor units re-establish communication and E1 clears.
• Step 5 – Board diagnosis: If wiring is correct and E1 persists, one of the control boards may have a failed communication circuit. Inspect both indoor and outdoor PCBs for visible damage. Use Klimaire service documentation to check DC communication voltage between terminals. Replace the faulty board.

When to call a professional: Communication faults often require electrical measurements and board-level diagnosis. If you lack tools or experience, contact a Klimaire-certified technician.