If the windows become covered with an oily, greasy, or waxy film, clean them with glass cleaner. Follow the directions on the container.
Do not scrape or scratch the inside of the window glass. It could damage the thermal filaments and the aerial lines.
When washing the inside of the window glass, use a soft cloth dampened in lukewarm water, gently wiping the thermal filaments and the aerial lines.
Use of glass cleaning products could damage the thermal filaments and the aerial lines.