And vents INSIDE the fireplace that need shutting - not the flue!!!

[ironmaiden]

The energy auditor looked up the chimney of our fireplace with a flashlight.

The flue/damper was closed. BUT there is a vent in the damper that was open. We never knew it existed. Using a flashlight you can see these vents i.e. holes. There is a slide to shut them. However, DH said he'd probably have to use a hammer to shut them and the guy said he'd be covered in soot when he's done.
So the guy basically said that we've had a "window" open for the past 11 years.

Some chimneys have the control for this vent as part of the damper control. Ours pulls in and out and for some turning this lever to the right or left closes and opens these vents.

I guess the vents are for fine tuning the amount of air that gets to the fire.

[Katybird]

Thanks for the heads up. I will have to let my inlaws know about this.