Indoor unit shows E1 and stops operation shortly after starting

Safety first: Turn OFF the breaker supplying the air conditioner before opening any covers.

• Step 1 – Verify power and polarity: At the indoor and outdoor terminal blocks, confirm that L, N, and communication terminals match the wiring diagram on the unit cover. Correct any reversed or loose connections.
• Step 2 – Inspect communication cable: Follow the multi-core cable between indoor and outdoor units. Look for cuts, rodent damage, or crushed sections. Tighten all terminal screws. Replace the cable if insulation is damaged or conductors are exposed.
• Step 3 – Check outdoor unit power: Ensure the outdoor unit is receiving proper voltage. If the outdoor fan and compressor never attempt to start, the outdoor PCB may not be powering up.
• Step 4 – Reset system: After correcting wiring, turn power back on and wait 3–5 minutes. Try starting the unit again.
• Step 5 – PCB diagnosis: If wiring is correct and E1 persists, the outdoor main PCB or indoor main PCB may be defective. Check for diagnostic LEDs on the boards (if present) and replace the faulty PCB according to TCL service documentation.

Warning: Live terminals inside both indoor and outdoor units can cause electric shock. Use a qualified technician if you are not experienced with electrical testing.