Question 1

What does error code H62 (Panasonic) / L9 (Mitsubishi) u Panasonic & Mitsubishi and how to fix it?

Accepted Answer

Low water flow rate in heating circuit. Repair procedure: Clean the water strainer mesh and magnetic dirt separator, bleed the circulation pump, and verify underfloor heating loops are open.

Question 2

What does error code H70 / F20 u Panasonic & Mitsubishi and how to fix it?

Accepted Answer

Backup bivalent immersion heater overload / high compressor discharge temperature. Repair procedure: Reset the manual thermal cut-out button on the backup heater element or check its dedicated circuit breaker.

Question 3

What does error code F36 / H72 u Panasonic & Mitsubishi and how to fix it?

Accepted Answer

Faulty outdoor ambient temperature sensor or DHW cylinder sensor. Repair procedure: Replace the NTC temperature probe (thermistor) inside the DHW tank pocket.

Panasonic H62, H70, F20 & Mitsubishi L9, P8, U1 Fault Codes – Error Code Meaning, Troubleshooting & Repair

Error Code Reference Table for Panasonic & Mitsubishi and step-by-step repair procedure:

Error Code	Meaning / Fault Symptom	Most Common Cause & Repair Procedure
H62 (Panasonic) / L9 (Mitsubishi)	Low water flow rate in heating circuit	Clean the water strainer mesh and magnetic dirt separator, bleed the circulation pump, and verify underfloor heating loops are open.
H70 / F20	Backup bivalent immersion heater overload / high compressor discharge temperature	Reset the manual thermal cut-out button on the backup heater element or check its dedicated circuit breaker.
F36 / H72	Faulty outdoor ambient temperature sensor or DHW cylinder sensor	Replace the NTC temperature probe (thermistor) inside the DHW tank pocket.