I have a honeywell furnace that is blowing cold air. Could it be a fuse? The batteries in the thermostat are brand new. Don't know if this would cause it to blow cold air?

I have a honeywell furnace that is blowing cold air? I recently replaced the batteries in the thermostat, don't know if this related, as it was blowing cold air prior to replacing batteries. Could it be a fuse?

Exact brand and exact model number of furnace?

Honeywell Model S825D

That is the model number for the thermostat. We need the brand and model number for the furnace.