[DaveM1.]

I have an american standard freedom 80. The first burner is allowing flames to leak out of the back of the burner which triggers the open high heat device. What is causing this?

What is causing this?

 

[DaveM1.]

Can I fix this myself?

 

[how]

Pictures would help.
If this happens before the main blower comes on then...
you are probably talking about the gas backing out of the venturi opening of the burner because of a dirt/scale/rust obstructed burner diffuser.
Turn off the furnace power, remove the burners and wash them out.

 

[REP]

It sounds like you need a clean and check real bad.With that a gas pressure check and a draft check should be done.Ignoring this could lead to real bad medical problems.

 

[beenthere]

Does this happen as soon as the burners ignite, or only after the blower starts. if only after the blower starts. good chance you have a bad heat exchanger.