Display shows H0 or HO; microwave does not heat but other functions appear normal.

This is typically not a hardware fault but a safety feature.

• Step 1 – Try standard unlock: On many Bomann microwaves, press and hold the STOP/CANCEL or LOCK symbol key for 3–5 seconds until the H0 indicator disappears. Alternatively, press and hold START and STOP together (check your user manual).
• Step 2 – Power reset: If the lock will not clear, unplug the microwave for 5 minutes, then reconnect and try the unlock sequence again.
• Step 3 – Check keypad: If the lock icon remains and keys do not respond, the keypad or control PCB may be faulty (see keypad fault section).