What you are actually seeing
- The light, the fan and the turntable all work and food stays cold
- Heating that has become gradually weaker
- Heating only on high power
- A loud buzz with no heating
- Not this fault: Food that is hot outside and cold inside
Ranked causes on a Contoure microwave
- Low supply voltage — Ranked here because: a coach appliance can be fed from shore power, a generator, an inverter or the battery bank, and a supply that is present but weak produces faults that look like component failures
- Door interlock not making the cook circuit — Ranked here because: a door latch and gasket that has been slammed by road motion is a routine finding
- Power level set low — Ranked here because: coach appliances are used intermittently and stored for months, which produces its own fault pattern
- Too small a load or a cold-centred item — Ranked here because: coach appliances are used intermittently and stored for months, which produces its own fault pattern
- High-voltage diode, capacitor or transformer failed — Ranked here because: this is a wear part with a service life rather than a component that fails at random
- Magnetron output declining with age — Ranked here because: the high-voltage section is not an owner-serviceable area under any circumstances
What to check, and in what order
- Heat one cup of water on full power for two minutes and see whether it gets hot
- Confirm the oven is set to full power rather than a defrost or reduced level
- Try the oven on a different known-good outlet with no extension lead
- Note whether heating changes when the door is pressed firmly
Steps you can safely do yourself
- Try the oven on a different known-good outlet with no extension lead — Tools: none — Estimated time: about ten minutes
- Note whether heating changes when the door is pressed firmly — Tools: none — Estimated time: a few minutes
- Compare how long a standard task takes now against what it used to take — Tools: none — Estimated time: a few minutes
- If there is no heating with a good supply, unplug the oven and stop using it — Tools: none — Estimated time: a minute
- Heat one cup of water on full power for two minutes and see whether it gets hot — Tools: a cup of water — Estimated time: a few minutes
Safety
Safety
unplug-before-service
When to call a technician
the oven runs and does not heat with a confirmed good supply — this is the high-voltage section the oven trips a breaker when cooking starts heating comes and goes with the door position, since that is an interlock
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.
