Why Are the Cabinets Beside My Wall Oven Discolouring?

Flush inset is where it turns up most. The published minimum is an eighth of an inch of reveal on every side, with all four corners at exactly ninety degrees. Site work eats that: a deep scribe against a wall, a filler run past the opening, a casing that ends up shy of square, and the gap the intake was drawing through is half of what the drawing showed.

The cabinet fronts either side show it first because they are the nearest finished surface to an opening that is now venting where it should not. Lacquer yellows, a veneer edge lifts, a painted rail goes chalky along one line. The second contributor is a door that no longer pulls up square, which lays a steady ribbon of heat along one edge; look for marking that follows the door line rather than the vent line.