Indoor unit displays H1 and heating is delayed; outdoor unit may be in defrost mode.

Note: On many Chigo heat pump models, H1 is not a fault but an indication that the unit is in defrost mode.

• Step 1 – Observe duration: Defrost typically lasts 5–15 minutes. If H1 clears and heating resumes, no action is needed.
• Step 2 – Check outdoor coil: If H1 persists, inspect the outdoor coil for heavy ice buildup. Ensure the fan is running and the coil is not blocked.
• Step 3 – Clean coil and surroundings: Remove debris and gently clean the coil fins.
• Step 4 – Sensor/PCB check: If the unit stays in defrost or never enters defrost when iced, a technician should test the outdoor coil temperature sensor and defrost control on the outdoor PCB.