Can You Turn on the Heater When the Car Windshield is Frozen?
2 Answers
When the car windshield is frozen, you can turn on the heater. Physical De-icing: Car owners can prepare a hard plastic scraper, or use a specialized glass frost scraper, which is more convenient, faster, and keeps hands from freezing. When there is snow and ice on the windshield, use the plastic scraper or glass frost scraper to remove it. However, when removing ice and snow, be careful not to scratch the glass. Do not scrape back and forth with the plastic scraper or glass frost scraper; instead, push in the same direction. Maintaining Consistent Temperature Inside and Outside the Car: After using the car for the day, do not immediately lock the car and leave. Instead, open the doors to ventilate the car until the interior temperature drops to match the outside temperature (which takes about a minute). Then, turn on the power and use the wipers to brush off any remaining snow or water on the windshield. At this point, close the doors and lock the car. The next morning, simply sweep away the accumulated snow on the windshield. If there is no ice beneath the snow, you can drive off immediately.
It's fine to use the heater to defrost icy windows, but technique matters. Last time at -15°C, I was in a hurry and cranked the windshield defroster to max heat immediately after starting - ended up with a crack 'pop' sound before the ice fully melted. Now I know better: First press the AC button to dehumidify (don't fret about the slight fuel cost), wait until the coolant gauge reaches mid-level, then set to 26°C with medium fan speed. Always activate rear window heating wires simultaneously, gently using wipers to clear melting ice flakes. Keeping an ice scraper in-car is practical - scrape thin ice layers before heating to save 30 minutes. Never spray cold water during thawing, as thermal shock damages glass.
