Microwave / high-voltage system
Microwave Not Heating: Causes, Checks, and Repair Cost
A microwave that runs but does not heat may have a door switch, magnetron, diode, capacitor, or control issue. Internal repair can be hazardous.
Quick answer
What it means
A microwave that runs but does not heat can involve high-voltage parts. External checks are limited; internal microwave repair can remain dangerous even when unplugged.
Typical repair$90-$350
UrgencyHigh
Repair or replaceReplace is often worth comparing on countertop units; call a pro for built-in or high-value models.
Likely causes
- Door switch issue
- Magnetron or diode fault
- High-voltage capacitor issue
- Control board fault
Safe first checks
- Confirm the timer runs and the turntable or light behavior.
- Try a known microwave-safe cup of water for a short test.
- Check door closure and latch feel.
- Compare repair cost against replacement before internal service.
Likely parts and repair cost
Typical repair range: $90-$350. Parts or systems commonly considered:
- Door switch
- Magnetron
- High-voltage diode
- Control board
Stop and call a pro when
- Do not open high-voltage areas.
- Burning smell, arcing, or sparking occurs.
- The door latch is damaged.
Source trail
This guide starts with manufacturer support, public recall lookup, or safety references, then turns those sources into plain-language checks.
Questions people ask
Is microwave repair safe?
Internal microwave repair can be hazardous because high-voltage parts can hold charge.
Should I replace it?
For inexpensive countertop models, replacement may cost less than internal repair.