The short answer
A built-in oven door leaks because it has stopped hanging square, far more often than because the gasket has failed. Look at the gap all the way round a closed door: where the gap is tells you which part is at fault.
What you actually see and hear
- A gap at the top of the closed door with none at the bottom — The door has dropped on its hinges. This is the common one.
- The door will not stay put at part-open, or falls open — Hinge springs tired or a hinge failed.
- The gasket is flat, hard or pulled out of its clips — A genuine gasket fault and a straightforward part.
- The cabinet or worktop above the oven is discolouring — Heat is escaping into joinery. Take this one seriously.
- NEAR MISS - the outer door glass gets warm — Normal. Warm is not the same as leaking.
Causes, most likely first on this machine
- Hinge wear and a dropped door — First. A multi-pane door is heavy, spring hinges wear, and the result is a gap that starts at the top and grows.
- Gasket flattened, hardened or displaced — Second. Heat ages the woven gasket, and cleaning pulls sections out of their clips.
- Debris on the sealing face — Third, and free: baked-on spill on the frame holds the door fractionally open all round.
- Inner glass refitted incorrectly after cleaning — Fourth, and very common on doors designed to be split for cleaning - a panel out of position stops the door closing flat.
- Cabinet or oven not square in its housing — Last. If the housing has moved, or the oven was never shimmed properly, the door cannot sit square however good its parts are.
Check in this order, and why
- Look at the closed door from the side and from above — Where the gap is, and whether it is even, is the whole diagnosis.
- Open the door to part-open and let go — A door that falls or creeps has a hinge problem.
- Run a finger along the gasket cold, all the way round — Feel for flat, hard and missing sections, especially at the corners.
- Check the appliance is square and level in the housing — A built-in oven that was never shimmed will never seal properly.
What an owner can safely check
- Let everything cool, then inspect the gasket all round — Check the corners and the clips particularly.
Tools: torchAbout 15 min
- Clean the sealing face and the door frame — Baked-on residue holds a door open more often than people expect.
Tools: cloth, oven cleanerAbout 20 min
- Test the seal with a paper strip at several points around the door — Where it slides out easily, heat is leaving.
Tools: paperAbout 15 min
- Compare the top and bottom gaps of the closed door — A clear difference is hinge droop, not a gasket fault.
About 10 min
- Check the oven is level and square in its cabinet — Shims under the appliance are a legitimate and common fix.
Tools: spirit levelAbout 20 min
- STOP HERE before removing the door, the hinges or the inner glass panels — Spring hinges are under real tension and multi-pane doors are heavy.
Before you open anything
Safety
Switch the oven off at its breaker before touching anything - a built-in oven is wired into a dedicated circuit and there is no plug to pull. Let the cavity cool completely first; a fan oven holds heat in the cabinet long after the door is opened. If the appliance is part of a gas installation and you smell gas, do not switch anything on or off, leave the building, and call the gas utility from outside.
When to call a technician
Call for hinge replacement, for a gasket that has to come out with the inner panel, or for any oven that has to be drawn from its housing - all three are awkward, heavy jobs on a built-in appliance. Call promptly if the joinery above or beside the oven is discolouring, because sustained heat into a cabinet is a fire risk and not a cooking complaint. Cleaning the sealing face and checking the installation for square cost nothing and are worth doing first.
Nearest pages of this class
What this page does not cover
This page is written for the built-in fan oven class, not for one family or model line. Where a brand- or model-specific page exists for your unit it is the more specific answer and it is linked above, so go there first if your machine is named. What is deliberately not here: element and fan ratings, sensor resistance tables, hinge and gasket part numbers, terminal block details and cabinet cut-out dimensions, all of which differ by family and belong on the page for that family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
