LG [DOOR] fault codewhat it means and how to fix it

LG publish this one as a word rather than a code, and their text is the most practical thing in their whole microwave table: DOOR "indicates a problem with the door not being closed or the door latch not being engaged", and their remedy is to be sure no packing or foreign material is preventing the door from latching, to close the door firmly, and to check that a cooking rack is not out of position and stopping the door closing. The reference to packing is LG addressing a brand-new appliance with transit material still inside it, which sounds too obvious to publish and is one of the commonest first-use faults there is.

What sits behind the code is the mechanism that makes a microwave safe, and it is worth understanding because it explains why the appliance is so unforgiving about a door that is nearly shut. A microwave door is not a lid, it is a radiation shield, and the standard these appliances are built to defines not just a door interlock — a device that stops the magnetron running unless the door is closed — but a monitored door interlock, an interlock system with a supervision device watching it. LG’s own manuals describe the oven as having built-in safety interlocks, plural, and service literature across the trade describes a primary switch, a secondary switch and a monitor switch.

Every one of those switches has to change state for the appliance to run. A door held a millimetre off by a crumb, a bag of packing foam or a rack sitting proud will satisfy some of them and not the rest, and the appliance treats a partial answer as a no. That is the behaviour you are seeing, and it is the system working. The good news is that the causes LG list are all things you can look at from the outside, which makes this the one door-related fault in this category with a real owner remedy. The limit is also clear: LG say that if the code continues, service is required for a proper diagnosis. A door that will not latch on a clean, empty appliance is a hinge, a latch or a switch, and none of those is reachable without removing the cover.

1. 1

   Open the door fully and take everything out, including any rack, turntable support and — if the appliance is new — any packing, foam or cardboard still inside.

2. 2

   Look along the frame where the door meets the body and along the door edge itself. You are looking for anything raised: dried spatter, a crumb, a label, a bent trim.

3. 3

   Wipe the frame and the door edge with a damp cloth and dry them. Pay attention to the catches on the door edge and the slots they enter.

4. 4

   If you use a cooking rack, take it out and try without it. LG name it specifically, and a rack sitting a few millimetres proud is enough.

5. 5

   Close the door deliberately — firm and square, not a swing. If the code clears, put the rack back and check it clears again with the rack in.

6. 6

   If DOOR persists on a clean empty appliance with the door firmly shut, stop there. LG’s own instruction is that a continuing code needs a proper diagnosis.

   Do not try to hold, tape or wedge the door to make it run. Those switches are the radiation containment, and defeating them defeats the only thing keeping microwaves inside the cavity.