Fireplaces, Heating Stoves, Flues and Chimneys - fireplace help please

I purchased a 50 year old home with a fireplace last summer. I've grown up with wood stoves but I am not too familar with fireplaces.

First of all, can I use muriatic acid to "clean" up my bricks a little?

I also just found a vent in the back of my pit. It looks like a mail slot. What's this?

I have pics to share if someone can help me.

Thanks!

Tom

First step is to have the chimney cleaned and inspected by a professional. The inspection will reveal any cracked or missing mortar and whether or not a liner is needed. The crown needs to be inspected. If there is not a chimney cap, there should be one. The professional inspection is critical for the safety of you and your family to prevent chimney fires and carbon monoxide.

The slot in the back of the fireplace could be where a chain once was for adjusting the damper. The chimney professional will inspect the damper to assure that it is functioning properly.

If cleaning soot from interior bricks, soot cleaners are available at local hardware, home centers, and hearth stores. Do not use muriatic acid indoors. It is extremely dangerous.

Usefull, thanks.:thinker: