Summary of Beijing Haier Air Conditioning Repair Cases.
Haier KFR-71LW type air conditioner starts heating immediately upon startup.
Analysis and Maintenance: First, check the electrical wiring, which is found to be correct with no errors. Suspecting an issue with the four-way valve, we test its coil resistance, which turns out to be normal, and it functions properly when powered on. It is determined that the four-way valve is stuck. Considering that this unit is newly installed, the possibility of four-way valve damage is small; it may be slightly stuck. Using a wooden stick to repeatedly tap the four-way valve, after testing the machine at the Beijing Haier Air Conditioning Service Center, the fault persists, thus confirming that the four-way valve is damaged. Replacing the four-way valve resolves the fault.
Tip: When maintaining the four-way valve, do not replace it casually. If it's slightly stuck, it can often be repaired by tapping it repeatedly with a wooden stick, especially for air conditioners that have been used for a short period.