Panasonic · Air Conditioner

Panasonic Air Conditioner H99 error code

Difficulty: Easy · Cost: $0–$150 · Duration: 30–60m

The H99 error means your Panasonic air conditioner's indoor unit freeze protection has activated — ice has formed on the indoor evaporator coil. The unit stops cooling to allow the ice to melt and prevent damage to the coil and fan. This is most commonly caused by a dirty air filter restricting airflow or running the unit in very cold conditions. Cleaning the filter and allowing the ice to melt usually resolves it.

Common causes

Indoor air filter is dirty or clogged causing reduced airflow and ice formation on the coil
Air conditioner is being operated in very cold ambient temperatures
Low refrigerant level causing the evaporator to run too cold
Indoor unit fan has slowed or stopped reducing airflow across the coil

How to fix it

1

Turn off the unit and switch to fan-only mode to allow the ice on the coil to melt
2

Remove and clean the indoor air filters thoroughly
3

Make sure no furniture or curtains are blocking the indoor unit air intake
4

Wait until all ice has melted before restarting cooling mode
5

If H99 keeps returning after cleaning the filter contact a qualified technician to check the refrigerant level and indoor fan