Heating high pressure control activated — RUN LED flashes 8 times, TIMER LED flashes 7 times

What does 87 mean?

The system's high-pressure control has activated during heating operation and caused the compressor to stop. This indicates issues with refrigerant levels, closed service valves, or inefficient heat exchange during heating.

• Service valve is closed or partially obstructed
• Refrigerant is insufficient or overcharged
• Compressor lock or overload operation
• Faulty outdoor heat exchanger sensor

Click steps to track your progress.

1. 1

   Ensure all service valves on the outdoor unit are fully open.

2. 2

   Check the refrigerant level; it may be insufficient or overcharged, requiring adjustment by a technician.

3. 3

   Verify the outdoor unit has good ventilation and is not experiencing overload operation during heating due to environmental factors or blockages.

4. 4

   If the issue persists, the compressor may be locked or faulty, or the outdoor heat exchanger sensor could be malfunctioning.