Microwave runs but does not heat food; turntable and light operate normally, no error code displayed.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety warning: The high-voltage section is extremely dangerous. Only qualified persons should work beyond basic checks.
User checks:
- Verify you are using a microwave-safe container and that you are heating an adequate load (e.g., 250 ml of water).
- Try different power levels and programs to rule out a control setting issue.
- If the unit consistently fails to heat, discontinue use.
Service actions (qualified):
- Remove the cabinet and inspect the HV fuse and wiring.
- Test the magnetron, HV diode, and transformer according to Neff service data.
- Replace defective components with genuine Neff parts.
Because of the risk of electric shock and microwave leakage, most users should contact a Neff service technician for no-heat faults.