The BMW 3 Series F30 heat lamp (often referred to as the rear defogger/heat lamp or heating element lamp) is an electrical heating component designed to clear condensation, frost, or light ice from the rear glass and sometimes exterior mirrors.

Description:

• Type: Electrical heating lamp/element.
• Function: Provides localized heating when switched on, helping maintain clear visibility through the rear windshield (and sometimes side mirrors).
• Operation: Activated by the rear defrost button inside the cabin, it draws current from the electrical system and heats up rapidly.
• Location:
  
• Rear windshield (integrated as thin horizontal heating lines in the glass).
• Exterior side mirrors (optional, depending on spec).
• 
  
• Power Source: 12V electrical system, controlled via relay and switch.
• Common Issues:
  
• Burnt heating filaments (lines on the glass not heating).
• Blown fuse or relay failure.
• Broken wiring to the lamp/heating elements.
• 
  

⚠️ For BMW parts catalog, this is often referred to as rear window heating element or mirror heating element, not a conventional bulb-type lamp.

Do you mean the rear defogger heating element (in the glass) or the interior cabin heat lamp/bulb (like footwell or dome light that produces warmth)?