What To Do If Heater Is Blowing Cold Air - Web dirty or clogged air filters. If your furnace only blows cold air after you’ve turned on the heat, start your troubleshooting at the. Over time, air filters accumulate dust and debris, restricting the airflow and causing.
Web dirty or clogged air filters. Over time, air filters accumulate dust and debris, restricting the airflow and causing. If your furnace only blows cold air after you’ve turned on the heat, start your troubleshooting at the.