my furnace is in the basement I want to hook my tv on the firplace in the kitchen the same chimney that the furnance is hooked up to. It does not get hot I just wanted to make sure that it was safe an no gases can come thru after caulking the screws. Where can I find the step by step to hang tv hooked to furnace safely.
Assuming you're talking about a flat-panel TV, and that your TV location doesn't get too warm if you use the fireplace or the furnace, I don't see any problem with it - just make sure you use appropriate hardware for the type of chimney, such as lag bolts with expansion anchors if you have a brick chimney that is in good condition (no loose bricks or mortar). I think most modern construction codes would require a separate flue for the fireplace and the furnace anyway.
Most flat-panel TV wall-hanging kits will tell you to use the expansion anchors with lag bolts if securing to brick or concrete - you just have to drill the appropriate-sized hole with a masonry bit (and preferably a masonry drill, which is the same as a regular electric drill but has a high-speed vibration mode to give a sort of jackhammer effect that cuts through concrete & masonry much faster than just rotary grinding that you get with a regular drill).
The best place to hang a TV is at eye level (sitting down)- level with the middle of the screen.
Hanging a TV above the fireplace causes neck strain when viewing it.
Generally hanging a TV above a fireplace is a very bad idea. The heat, smoke, ash, will damage the TV plastic screen and destroy the TV.
It also leaves permanent scars in the bricks.
But if you must, and there's no heat from the fireplace, consider what it does to your neck.
I don't know who came up with the idea of hanging a TV above the fireplace, but this was not a genius idea.