Furnace will not lite and blower keeps running blowing cold air?

If your furnace won't light and the blower is running continuously, it could be due to a few issues. Common causes include a faulty thermostat, a clogged air filter, or a malfunctioning ignition system. Check the thermostat settings and replace the air filter if it's dirty. If these steps don’t resolve the issue, it may be best to call a professional technician for further diagnosis and repair.