What you are actually seeing
- Scorch marks on the cavity wall or the door
- A smell of burning with no food in the oven
- Flashes or arcing inside the cavity
- A burning or hot-plastic smell
- Not this fault: A smell of burnt food only
Ranked causes on a Contoure microwave
- Circuit cannot carry the load or is shared — Ranked here because: the converter and the transfer switch sit between the appliance and whatever is actually powering it, and both fail in ways that look like a dead machine
- Loose or damaged plug, cord or outlet — Ranked here because: a coach installation is tighter than any domestic one and the venting and clearance shortcuts taken during the build show up as faults later
- Grease accumulation in an over-range unit — Ranked here because: an RV vent run is short, tightly bent and easy to crush behind the appliance
- Metal in the cavity — Ranked here because: coach appliances are used intermittently and stored for months, which produces its own fault pattern
- Waveguide cover burnt or missing — Ranked here because: this is a wear part with a service life rather than a component that fails at random
- Food debris burnt onto the cavity or ceiling — Ranked here because: a restriction builds gradually, so performance falls off long before anything stops
What to check, and in what order
- Feel the plug, the cord and the outlet for heat and look for discolouration
- On an over-range unit, wash the grease filters in hot soapy water
- Stop the oven and unplug it
- Look at the cavity walls, the ceiling and the waveguide cover for scorching or holes
Steps you can safely do yourself
- Stop the oven and unplug it — Tools: none — Estimated time: a minute
- Look at the cavity walls, the ceiling and the waveguide cover for scorching or holes — Tools: flashlight — Estimated time: about ten minutes
- Check whether the arcing happens with one particular dish, wrapping or accessory — Tools: none — Estimated time: a few minutes
- Clean the cavity thoroughly, especially the ceiling and around the waveguide cover — Tools: warm soapy water, cloth — Estimated time: about twenty minutes
- Feel the plug, the cord and the outlet for heat and look for discolouration — Tools: none — Estimated time: a few minutes
Safety
Safety
unplug-before-service branch-circuit-15-20a
When to call a technician
the oven trips a breaker the moment it starts cooking there is a burning smell from the vents rather than from the cavity the waveguide cover is burnt, or there is scorching on the cavity or the door
Nearest pages
What this page does not cover
Not this fault: the family pages for the refrigeration, cooking and laundry lines Not this fault: model-specific pages once the model and serial label is read
Links: - [Common Contoure Microwave Problems](/blog/contoure-microwave-problems) - [Common CONTOURE Dryer Problems](/blog/contoure-dryer-problems) - [Common CONTOURE Refrigerator Problems](/blog/contoure-refrigerator-problems) - [Contoure Microwave: Abnormal Noise or Vibration](/blog/contoure-microwave-abnormal-noise)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
