Microwave not heating: causes and fixes
A microwave that lights up and turns the plate but no longer heats almost always has a failed power component. It is one of the few appliances where repair genuinely needs comparing against the price of a new one.
Safety first
Never open a microwave's casing: its high-voltage capacitor stays charged even when unplugged and can cause fatal electrocution. These repairs are for professionals only.
The causes, from most to least common
Check them in this order: the first ones are free and solve the majority of cases.
- 1
Faulty door interlock
commonHow to check: The door closes badly, or the appliance starts then stops. The latch microswitches no longer trigger.
Fix: Replacement of the microswitches by a professional - an inexpensive part.
ProfessionalEstimated cost: 60 to 120 € - 2
Worn magnetron
commonHow to check: Everything works normally (light, turntable, fan) but food stays cold, usually after several years of use.
Fix: Replacement of the magnetron by a professional.
ProfessionalEstimated cost: 100 to 180 € - 3
Failed diode or high-voltage capacitor
commonHow to check: An unusually loud hum, sometimes a bang, with no heating.
Fix: Replacement by a professional only.
ProfessionalEstimated cost: 80 to 150 € - 4
Defrost mode or reduced power
less commonHow to check: Check the power setting: at 10%, food barely heats.
Fix: Set it back to full power.
EasyEstimated cost: 0 €
If you take this out-of-warranty microwave to a QualiRépar-certified repairer, 20€ comes off the invoice.
| Repair by a professional | 60 to 180 € |
| Repair bonus deducted | - 20 € |
| What you pay | 40 to 160 € |
Indicative estimate: the real price depends on the part, the model and the call-out. The bonus can never exceed the invoice total.
How to claim the repair bonus →When to call a professional
Any internal work on a microwave must go to a professional: the high-voltage capacitor stays charged even unplugged. On an entry-level microwave over 6 years old, a 120 € quote often exceeds the price of a new appliance.
Find a repairer near you →Frequently asked questions
My microwave runs but doesn't heat, what should I do?
Check the power setting first. If that is correct, it is a power component (magnetron, diode or high-voltage capacitor): the work must go to a professional and should never be attempted yourself.
Is it worth repairing a microwave?
On an entry-level model, rarely: a magnetron fitted (100 to 180 €) often approaches the price of a new appliance. On a built-in or high-end model, however, repair remains well worth it.
Your microwave may be nearing the end of its life: a microwave lasts 6 to 10 years. Beyond that, an expensive repair is harder to justify.