Microwave Not Heating

Microwave runs but food stays cold

80%

80% chance this is caused by:

Failed magnetron or blown thermal cutout

🔧 The Exact Part You Need

Magnetron

$45

Buy on Amazon →

Thermal Cutout Fuse

$10

Buy on Amazon →

Total parts cost: $55. Same-day shipping available on most items.

🔨 Tools You'll Need

Multimeter

$25

Amazon →

Multi-Bit Screwdriver

$12

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Hard · 30-45 minutes

Parts: $55 vs $$100-500 to replace

📋 Step-by-Step Instructions

UNPLUG the microwave — capacitor holds lethal charge

Discharge the capacitor with an insulated screwdriver across terminals

Remove outer cabinet screws

Test thermal cutout with multimeter — no continuity = blown

If thermal cutout is fine, test magnetron resistance

Replace the failed component

WARNING: If replacing magnetron, do not touch the ceramic insulator

Not comfortable with this repair?

This is rated as a hard repair. If you'd rather have a pro handle it, a service call typically costs $100-200 plus parts. For a major component, it may be worth the peace of mind.

Check what a professional would charge: See repair costs on FixrCost →

Frequently Asked Questions

How much does it cost to fix a microwave that's not heating?

The part costs about $45. If you do it yourself, that's your total cost. A professional service call would add $100-200 in labor, bringing the total to $195.

How long does this microwave repair take?

This repair is rated "hard" and typically takes 30-45 minutes. The most time-consuming part is usually accessing the component, not the actual swap.

What if this isn't the problem?

Our diagnosis is 80% likely based on the symptom you described. If replacing this part doesn't fix it, the next most common cause for "microwave runs but food stays cold" would be related to the wiring harness or control board. In that case, consider calling a professional.

Should I just replace my microwave instead?

A new microwave costs $100-500. If yours is well under 7-10 years old, a $45 repair is far more cost-effective. If it's near end-of-life and has had multiple issues, replacement starts making more sense.