I had a power surge and had to replace the control board st9141a1002 thermostat and transformer on my furnace that is 9 years old made by consolidated industries. The furnace will come on and blow heat for about 6 minutes and shut down. The diagnostic light will flash 2 times... primary limit circuit open. Turn off ac power it resets bright/dim... normal operation. {repeat} Can you give me an ideal what to check for. "

My first guess would have been the circuit board but you have already replaced that part. Since you had a power surge it could be almost anything. The furnace has a limit control disc in the furnace. It could be out of value causing this problem OR the it is also possible that

registers are closed blocking heat transfer.
Cold air returns blocked
Air filter dirty
Gas valve needs adjustment .(to high a BTU imput)
Blower speed to slow allowing heat build up in unit.

I would roll with the limit circuit device. That can be easily replaced. Unless you can see the other items as being a problem.