If you do not close it then you basically have a hole in your roof that is sucking out all the warm air. This will lead to even higher heating and cooling costs.
the flue should be opened
No. The flue must be open to allow the carbon monoxide to escape from the house.
Yes- but open before use.
When the fire is burning, until the ashes are cold. The damper should be open at these times.
You have to, or the fire is going to burn way too hot and not last very long. Depends on the type of wood you use also.
It needs to be open when lighting a fire. Close it when not in use. If you have any doubt which is which, look up the flue with a flashlight.
When burning the firplace, flue must be open to avoid death/ illness from carbon monoxide.
Is this an insert into a previous wood burning fireplace? Direct vent or vent free? BTUs?
The purpose of the fireplace damper is to keep the outside elements, outside. The damper is opened only when there is a fire in the fireplace.
No. Closing the firplace flue will not make any difference in damage to you home. Closing it will only waste time better spent taking cover.
the flue is the part of the fireplace that goes from the firebox to the outside of the building.
Yes, there are automatic fireplace flue dampers available for sale on the internet. Check out www.fluesentinel.com and www.actionair.co.uk or fireplace showrooms near you for more detailed information.