Symptoms
- Some parts of food are hot while others stay cold
- Turntable spins normally
- Food heats fine when stirred or rearranged partway through
- Problem is more noticeable with larger or dense food items
Likely causes
- CommonTurntable not rotating fully or consistentlyUneven rotation means some areas of food get more exposure than others.
- CommonFood container or shape blocking even exposureDense or oddly shaped food can create cold spots regardless of the microwave's condition.
- PossibleWeakening magnetron outputAs magnetrons age, they can still work but heat less powerfully and less evenly.
- PossibleDamaged wave guide cover affecting energy distributionA burned or warped cover can distort how microwaves spread through the cavity.
What to do
- Confirm the turntable spins freely and completes full rotations as described in the turntable guide.
- Stir or rotate food manually partway through cooking for dense or large items, which is normal best practice for any microwave.
- Check the wave guide cover for visible burn marks or damage as described in the sparking guide.
- Test heating a full cup of water for 2 minutes and see if it reaches a consistent near-boiling temperature throughout, which suggests decent overall output even if food itself heats unevenly due to shape.
- If the turntable and wave guide check out fine, uneven heating with denser foods is often normal and improved by stirring.
- If a full cup of water doesn't heat well overall, or unevenness is severe on simple foods like a mug of water, have a technician check the magnetron.
Tools and parts
Microwave wave guide coverSearch: “microwave wave guide cover replacement”
When to call a pro
If basic checks don't explain the unevenness, especially with simple foods like a mug of water, have a technician test the magnetron's output.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.