The second major safety concern would be ventilation.
Diy gas furnace replacement.
Turn off the power switch again and shut off the gas by giving the valve one quarter turn.
If you are replacing an existing furnace you just need to carefully extract the old furnace from the big metal boxes then seal the new unit to the same boxes.
Drain line to your vacuum hose.
The main issue will be safety for not only installing a furnace but mainly when dealing with a gas line and exhaust of the furnace.
After all blowers are basically just large fans.
Fixing a malfunctioning blower may be less daunting than you think.
Vacuum everywhere you see dust.
Remove the door on the front of the furnace cabinet to give you access to the blower it might be on a slide out drawer check the number stamped on the belt and get an exact replacement from a home center or heating supply outlet.
The other for distributing it.
To get at the back of the burners tape a 20 in.
Vacuum the furnace burners and the furnace base.
Most furnace units will already have a gas line run so making sure the connections are secure and there are no leaks will be one of the main safety concern.
Furnaces consist of two main operating systems.
First turn off all power to the unit and turn off the gas at the gas valve that serves the furnace.
Cool air also called return air gets sucked in through the bottom of the furnace heated and blown out the top supply.