85 — Voltage shortage, overvoltage, PAM error, or open phase primary current sensor error

What does 85 mean?

This error covers a range of power supply issues including voltage fluctuations (too low or too high), a PAM (Pulse Amplitude Modulation) circuit error, a fault in the primary current sensor, or an open phase in the power supply.

• Unstable or incorrect power supply voltage.
• Faulty power board components.
• Loose or damaged power wiring connections.
• Primary current sensor malfunction.

Click steps to track your progress.

1. 1

   If comfortable and qualified, check the main power supply voltage to the outdoor unit with a multimeter.

2. 2

   Inspect all power wiring connections to the outdoor unit for looseness, corrosion, or damage.

3. 3

   Ensure the main electrical panel breakers supplying the unit are fully engaged and haven't partially tripped.

4. 4

   Power cycle the entire system by turning off the main breaker for at least 10 minutes, then turn it back on.

5. 5

   If the error persists, an electrician or qualified HVAC technician is needed to inspect the electrical system and internal components.