The short answer
On Forno a door that will not seal or latch is most often a trim kit or cabinet loading the door. Ranked that way because a built-in microwave is held square by its trim kit, so the install is part of the appliance here rather than something that happened once.
What you observe
- There is a visible gap, wider at one end than the other — The door or the hinge is out of square, which is a repair rather than an adjustment.
- Baked-on residue along the flat faces where door meets frame — The most common cause and the one an owner can fully resolve.
- NEAR MISS: the machine keeps running with the door open — Stop using it immediately and switch it off at the breaker. That is a failed interlock, not a door adjustment.
Causes, most likely first on Forno
- The trim kit or cabinet is loading the door — First on a fitted machine, which is only ever as good as its installation. A built-in machine that has shifted in its aperture, or a trim kit tightened unevenly, pulls the frame slightly out of true and the door stops meeting it. The machine itself is fine and the install is not.
- The latch hooks or the strike are worn — Second: on a fitted machine this is the next thing genuinely yours to check. The door has to be pushed harder than it used to, or held to start a programme. The plastic hooks that press the interlock switches wear, and once they no longer press them fully the machine will not run even though the door looks shut.
- The hinge or the door has dropped out of square — Third. A heavy door on a built-in machine, or one that has been pulled on, sags on its hinge until it no longer meets the frame evenly.
- The door, the inner screen or the interlocks are damaged — Last, and it is the reason the order above matters. A dented door, a torn or perforated inner screen, a cracked frame, or a machine that keeps running when the door opens.
Check in this order, and why
- Open the door and see whether the frame sits square in the cabinet aperture — On a built-in machine this is the cause that is not in the appliance at all.
- Close the door and watch whether it latches with a normal push — A door that must be held is telling you the latch no longer reaches the interlocks.
- Close the door and look at the gap along the top and along the bottom — An uneven gap is a mechanical fault you can see from a metre away, and it is not an owner adjustment.
What an owner can safely check
- Check the machine sits square in its aperture with even clearance all round — If it does not, the installation needs correcting before the door is blamed.
Tools: torchAbout 15 min
- Close the door normally several times and note whether it catches every time — Do not force it and do not pack the latch with anything.
About 5 min
- Compare the door gap at the top and the bottom, and note any visible twist — Stop there.
About 5 min
- STOP HERE if the next step needs a meter on live terminals — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Never defeat, tape, pack or bypass a microwave door interlock for any reason, and never run the machine with the door damaged, bent or held shut. Do not open the outer casing: the high-voltage capacitor inside can hold a lethal charge long after the machine is unplugged, which is why the inside of a microwave is not owner territory at any skill level. Everything on this page is done with the casing closed.
When to call a technician
Call, or replace the machine, the moment the door is bent, the inner screen is torn or perforated, the frame is cracked, or the machine runs with the door open. Call as well when the latch has to be held, because worn interlocks are a safety part and not a convenience one. Cleaning the sealing faces is the only fix on this page an owner completes alone.
Nearest pages of this class
What this page does not cover
This page covers the brand and the microwave class, not one family or model line. Where a family-specific or model-specific page exists for your unit, that page is the more specific answer and it takes precedence over this one. Not here: part numbers, wiring colours and component locations, which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
