Troubleshooting Tips for Microwaves from Major Appliances in Calgary

Minimize the possibility of electric shock. Unplug the appliance from the power supply or disconnect power at the circuit breaker before attempting any maintenance or cleaning.

Normal Operational Characteristics

It is normal to experience any of the following with a microwave oven:

  • Steam or vapor escaping from around the door. This does not mean that the unit is leaking microwave energy. The door is designed to allow heat and steam to escape to prevent the overheating of the unit. It is normal to see some condensation between the door panels, unless the condensation does not dissipate within a reasonable amount of time.
  • Light reflection around door or outer case. The light is located outside the oven cavity and can reflect light out around the hinge, door, outer case, and oven lamp access cover.
  • Dull thumping sound or hum while cooking at power levels other than high. When using a power level other than HIGH or 10 the magnetron tube cycles on and off to obtain the lower power. This cycling of the magnetron tube causes this dull thumping, pulsating, or humming noise. When combination cooking in microwave/convection models, the cycling of the convection element and fan will alternate continuously with the hum of the magnetron and the fan.
  • Humming noise when the microwave is not in operation. The transformer emits a slight humming sound that is usually not noticed. The transformer is used to power the clock.
  • The interior fan will run continuously while the microwave is in operation to constantly circulate the air to cool the working parts.

Excessive Moisture or Condensation

  • Condensation inside the unit is normal and especially prevalent when cooking foods of high moisture content for extended periods of time either inside the microwave or on a cooktop beneath an over the range microwave.
  • Steam and vapor escaping from around the door is normal.
  • If minimal moisture is noticed between the glass, allow the microwave door to stand open for approximately 15 minutes to accelerate the dissipation of the moisture.

Warm Cavity or Case

Cooking foods in a microwave oven for an extended period of time can cause a heat transfer not only to the internal oven walls and floor, but to the external cabinet as well. This condition is considered normal.

Power Failure

If a power failure should occur, a microwave, depending on the model, may display "PF" or "8888". Both display codes can be cancelled and normal operation resumed by touching the CLEAR pad. You may now reset the clock on models so equipped.


  • First-time usage of a microwave may produce some smoke. This is typically a very small amount and is perfectly normal.
  • An electrical odor in new machines can be normal because the electronic board is "curing" as the circuit board material is heated for first few uses.

On microwave/convection models, dust particles can accumulate on the convection element and burn off when in use producing a small amount of smoke. Once dust has been burned off, the smoke will dissipate.