Panasonic H97 fault codewhat it means and how to fix it
An inverter or magnetron fault — and a counter. Panasonic state three H97 events disable the oven permanently, even after the faulty part has been replaced.
Take care
Get a qualified appliance engineer to look at your Panasonic H97
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What H97 means
H97 is one of the self-diagnostic failure codes on Panasonic’s inverter microwaves, and their service documentation puts it in a family: H95, H97, H98 and H99 are described as the provided failure codes indicating magnetron and inverter circuit problem areas. Their UK support answer goes one step further and points H97 and H98 together at the magnetron — the component responsible for generating microwave energy — while allowing that it could be the magnetron itself, the high voltage circuitry, or related components. That is as specific as Panasonic get in public, and it is the same answer for both codes.
What one of their service manuals adds is the part that changes what you should do, and it is not in any owner document we could find. The appliance counts these events. In Panasonic’s words: if three times H97 or two times H98 exist, the microwave oven can not be used any more, even if the defective parts already be replaced and unplugged and plugged in again. One caution about where that comes from: the manual that documents the counter covers 120-volt North American inverter models, and the 220–240-volt service manual we read for Panasonic’s NN-ST657 family carries the same H-code family and the same test mode but says nothing about a counter. Whether a UK model keeps the count is something Panasonic have not published either way, which is a reason to mention it when booking rather than a reason to assume it. Read that carefully, because it has a practical consequence that costs people money.
A microwave that has hit the count is permanently disabled by its own control board, and fitting a new inverter or a new magnetron does not bring it back. Nor does the standard power cycle. It needs a service reset sequence — entered with the door open, holding Start until the buzzer sounds, and stepping through with Stop/Reset — which also displays the total magnetron usage hours and the recorded number of H97 and H98 events. An engineer who does not know the sequence exists will replace the right part, find the oven still dead, and reasonably conclude the fault is elsewhere. If you are booking a repair on a Panasonic inverter model showing this code, the sequence is the thing to mention.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Inverter power supply has failed | Panasonic group this code with the inverter circuit, and their instruction is to replace the complete unit rather than repair the board. | Common |
| Magnetron fault | The other half of the family description. The service test checks for microwave oscillation, which is the tube doing its job. | Common |
| Lockout count already reached | Distinct from the original fault. The oven refuses to run because of its own event counter rather than because a part is faulty. | Occasional |
| Poor chassis earth to the inverter board | Panasonic devote a specific warning to the inverter grounding plate, saying an ungrounded board exposes the user to very high voltages. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£120–£250
Time on site
10 minutes
An inverter unit or a magnetron with a visit is typically £120 to £250. Panasonic’s instruction is to replace the complete inverter unit rather than repair the board, which puts a floor under the part cost.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Panasonic fault codes
- H95Get it checkedPanasonic’s UK support answer puts H95 on the inverter circuit; their service manuals decline to separate it from H97, H98 and H99 at all.Related: magnetron and high voltage
- H99Get it checkedThe catch-all. Panasonic UK describe H99 as a general code for a problem with no code of its own; their service manuals file it with the magnetron.Related: magnetron and high voltage
- DUsually simple to fixDemo mode. The appliance lights up, counts down and appears to work while making no microwaves at all, and it survives being delivered to you.Related: same brand
- CoolingUsually simple to fixNothing is wrong. Panasonic publish this one plainly: the fan is clearing heat off the electronics, and the word goes away when it stops.Related: same brand
- HOTUsually simple to fixThe cavity is still too warm from the last thing you cooked for an automatic programme. Manual cooking still works, and opening the door speeds it up.Related: same brand
- ChildUsually simple to fixThe child lock. The keypad is dead, the door still opens, and on Panasonic’s UK models three presses of Stop/Cancel clears it — three presses of Start is what set it.Related: same brand
Own a Panasonic microwave? Save it and its codes come first next time.
Related guides
Common questions about Panasonic H97
Panasonic list this code on their website. Why does one page explain it and another not?
Both are theirs and we cannot account for it. Their troubleshooting tool offers H97 as a selectable code and returns a heading with no text, and the same is true of ten other H-codes, E05, E06, E08 and "Service". A separate answer on their UK support portal does explain it, pointing H97 and H98 at the magnetron with the caveat that it could equally be the high voltage circuitry or related components. Neither page mentions the lockout counter, which is the thing on this page most likely to affect what happens to your appliance.
My oven was repaired and it still will not work.
That is the single most likely reason to be reading this page, and it is expected behaviour rather than a second fault. Panasonic state the appliance cannot be used any more once the count is reached, even after the defective parts have been replaced and the oven unplugged and reconnected. The service reset sequence is what clears it.
Can I do the reset myself?
The sequence is documented and it needs no tools, so mechanically you could. We are not going to walk you through it, for one specific reason: the counter exists to stop an oven being run repeatedly with a fault on its high-voltage side, and clearing it without fixing that is defeating a protection rather than repairing an appliance. Give the sequence a mention when you book instead.
Is it worth repairing?
An inverter unit or a magnetron plus a visit is frequently most of the price of a new microwave, and Panasonic inverter models are not the cheapest to start with. Ask for the diagnosis and the part price before authorising, and ask what the recorded magnetron hours are while the engineer is in the service display — that is a fair guide to how much life was left in it.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
- Manufacturer support portal
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.