ErrorCodeDoctor
Panasonic · Microwave

Panasonic Microwave H99 error code

Difficulty: Hard · Cost: $100–$300 · Duration: 5m

The H99 error means your Panasonic microwave detected a fault with the inverter's on/off control circuit. The inverter controls when and at what level microwave power is delivered to the magnetron. When the on/off control circuit develops a fault the microwave cannot operate the magnetron safely and stops. H99 is related to H97 and H98 and all three indicate faults in the inverter and magnetron system. A power reset sometimes clears it but a returning H99 requires service centre inspection.

Common causes

  • Inverter on/off control circuit has malfunctioned
  • Power surge caused a temporary fault in the inverter circuit
  • Inverter board component has failed

How to fix it

  1. 1

    Unplug the microwave for 5 minutes and plug it back in to attempt a reset

  2. 2

    If H99 returns stop using the microwave and contact a qualified technician

  3. 3

    Do not attempt to open or repair the inverter circuit — it operates at dangerously high voltages

Related Panasonic Microwave error codes

1

Cooling

The cooling fan is running to cool down the internal components — not an error

easy
2

Child Lock / Key Symbol / LOCK

Child lock is active — the control panel is disabled

easy
3

D

Demo Mode is active — the microwave will not heat

easy
4

E01

An internal fault was detected — the microwave requires service

hard

H99 error — frequently asked questions

What does the H99 error mean on a Panasonic microwave?

The inverter on/off control detected a fault

What causes the H99 error?

The H99 error is usually caused by: Inverter on/off control circuit has malfunctioned; Power surge caused a temporary fault in the inverter circuit; Inverter board component has failed.

Can I fix the H99 error myself?

This is rated a hard fix — it often requires tools, parts, or experience, and may be safer left to a professional technician.

How much does it cost to fix the H99 error?

Fixing the H99 error on a Panasonic microwave typically costs $100–$300, depending on parts and whether you do it yourself or hire a technician.

Is it safe to keep using my microwave with the H99 error?

We'd recommend addressing the H99 error before continuing to use the microwave, since hard-rated issues often involve a real fault rather than a minor glitch.