H2
Oster Convection heater overheat or thermal fuse open

Microwave displays H2 and will not start; may occur on convection/grill models.

Advertisements

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.

Advertisements

Possible Causes

Open convection thermal fuse, Blocked convection airflow, Failed convection fan motor, Shorted convection heater element

How to Fix / Troubleshooting

Safety first: Unplug the unit and allow it to cool completely.

  • Check for blocked vents: Make sure nothing is covering the top or rear vents. Remove any foil or covers used inside that may have blocked airflow.
  • Test convection-only mode: If available, try starting a convection cycle. If H2 appears immediately, the convection safety circuit is likely open.
  • Advanced testing: With the cabinet removed and power disconnected, locate and test the convection thermal fuse for continuity. Replace if open, using the exact Oster-rated fuse.
  • If fuse is good: The convection heater or fan may be faulty and should be tested and replaced by a technician.
Advertisements

Repair Difficulty

Professional Required 5/5

Required Part

Convection Thermal Fuse
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements