LG F5 fault codewhat it means and how to fix it
LG call this a Damper Switch Error. A damper is the vent flap on an over-the-range model, so only those appliances can show it.
Take care
Get a qualified appliance engineer to look at your LG F5
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 F5 means
F5 is published by LG as "a Damper Switch Error", and the first useful thing about it is that it identifies your appliance. A damper is a motorised flap that decides where an extractor sends the air it has pulled in, and it exists only on over-the-range microwaves — the type installed above a hob with a hood built into the underside. A countertop microwave has no damper, no extractor and nothing this code could refer to, so if you are looking at a freestanding appliance, read the display again.
On the models that do have one, the flap switches between two modes. Recirculating sends air through a charcoal filter and back into the room. Ducted sends it outside through a duct in the wall or ceiling. The damper is what moves between those paths, and a switch tells the control board which position it has actually reached rather than which one it was asked to reach.
When the board asks for a position and the switch does not confirm it, the appliance has an extractor whose destination it cannot vouch for, and it reports the fault. Why it bothers is worth spelling out, because on the face of it a stuck flap is a nuisance rather than a hazard. An over-the-range microwave sits directly above a hob, which is the most thermally hostile position any domestic appliance occupies. Its own cooling depends on that airflow being where the appliance thinks it is. A damper jammed in the wrong position does not just stop extraction working, it changes the thermal environment of the electronics sitting above a source of open heat. LG say service, and the switch and its linkage are behind the outer cover, which on a microwave is not a cover to remove.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Damper flap mechanically jammed | Grease from the hob below stiffens the linkage over years until the flap no longer reaches either end of its travel. | Common |
| Damper switch failed | The flap moves correctly and the switch no longer confirms it, so the board is left without a position to trust. | Common |
| Wiring or connector to the switch | An open circuit at the plug reads exactly like a switch that never closes, and is far cheaper to fix. | Occasional |
| Damper motor or actuator failed | Nothing drives the flap, so it stays where it was and the confirmation never arrives. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£80–£170
Time on site
1h 30m
Damper switch or actuator with a visit, around £80 to £170. Over-the-range models cost more to work on than countertop ones because the appliance usually has to come off the wall.
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 LG fault codes
- F2Get it checkedLG describe a thermistor problem putting the temperature in the unit out of range. It is the reading that is wrong, not necessarily the cavity.Related: overheating and cooling
- F17Get it checkedPublished by LG as a problem with the temperature sensor. Their F2 entry covers an unusable reading, so this is the sensor itself being at fault.Related: overheating and cooling
- F3Get it checkedLG document this one twice and differently. One article says wipe the touch panel, the other says the control panel is faulty and needs service.Related: same brand
- LOCUsually simple to fixNot a fault. LOC is LG’s child lock, and it releases by holding STOP/CLEAR until the display drops it.Related: same brand
- DOORGet it checkedThe word DOOR rather than a number. LG say the door is not closed or the latch is not engaged, and they include transit packing as a cause.Related: same brand
- F16Get it checkedLG say a heating issue was detected. They publish F19 with word-for-word identical text, so both codes land here.Related: same brand
Own a LG microwave? Save it and its codes come first next time.
Related guides
Common questions about LG F5
My microwave sits on the worktop. Why am I seeing F5?
You should not be, because a countertop appliance has no damper. Check the display again — F5 is easy to confuse with F6, which LG do not publish at all, and with S5 or E5 on other brands. If it really is F5 on a freestanding LG, quote it to LG directly, because their documentation ties this code to a part your appliance does not have.
Can I use the hob underneath in the meantime?
You can cook, but you may have no working extraction and you should assume the microwave above is running hotter than it was designed to. That is the real reason to deal with this reasonably promptly rather than living with it for a year.
Is the filter the same thing as the damper?
No. The charcoal filter cleans recirculated air and is a consumable you replace yourself; the grease filters underneath wash in the sink. The damper is the flap that decides whether air goes through the filter or out of the duct, and it is inside the appliance.
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 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.