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Cold oven, slow oven and uneven oven are three faults that share a page and not much else. Establish which one you have first, because the checks diverge immediately. On the MAS models the bake and broil elements are switched separately, so an oven that broils but will not bake has already told you which half to look at.
How this shows up
- The element glows in patches or not at all — Look along the element during a preheat with the light on: patchy glow, a dark section or a swollen blister is a diagnosis without a meter.
- It heats but takes far too long to preheat — A partially failed element, a bad seal or a sensor reading high. Slow is a different list from cold.
- Food browns on one side only — Airflow or a sealing problem rather than a heating one, and it usually has a cheaper answer.
- The broil works but the bake does not — Two separate elements and two separate switching paths, so this observation is worth a great deal.
- NEAR MISS — The oven is dead — no display, no light, nothing — That is a supply or control fault rather than a heating one, and it belongs on the electrical page.
Causes, most likely first
- The convection fan or its motor — It is easy to confirm: open the door mid-preheat and listen, or watch the fan through the glass with the light on. This ranks first here because the checks under it only make sense once it has been ruled out. That is where the MAS order departs from the brand-wide one: the convection fan or its motor moves ahead of a worn door seal or a door that does not close square because it is confirmed by watching rather than by testing.
- A failed bake or broil element — They fail one at a time, which is why an oven that broils but will not bake points immediately at the bake element rather than at the control.
- A worn door seal or a door that does not close square — It is checked by eye and by hand in a couple of minutes with the oven cold.
- The oven temperature sensor or its calibration — The sensor tells the control how hot the cavity is. When it reads high, the oven stops heating early; when it drifts, the oven never settles where it should.
What to check first, and why
- First — listen and look for the convection fan — Look through the door glass with the light on mid-preheat. A convection fan that is not turning explains uneven cooking completely.
- Second — watch the element through a preheat — Set a bake temperature with the oven empty and the light on, then watch. A dark element, a patchy one or a visible split has answered the question already.
- Third — check the door gasket all the way round — With the oven cold, run a hand along the seal for hardening, gaps and missing sections, and look for heat marks on the trim above the door. A leaking door explains slow and uneven before anything else does.
- Fourth — measure the cavity with an oven thermometer — Put a thermometer in the centre, let the oven settle properly rather than reading it during preheat, and write down the difference.
Before you open anything
Safety
Switch the oven off at its breaker before any panel comes off — a large cooking appliance sits on its own high-current circuit and a capacitor in the control can hold a charge after the power is off. Let the cavity cool completely before touching an element or a seal. If you smell gas at any time: do not switch anything on or off, leave the building, and call the gas utility or your emergency number from outside. Do not look for the leak yourself.
Where the owner job ends
Call when the element looks intact and never glows, when a thermometer shows the oven missing its target by a wide margin, or when a gas oven glows without lighting. Call immediately, from outside the house, if you smell gas at any time.
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Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
