I own a hair salon and I have a Goodman furnace near the ceiling (small attic), and the guys I contracted have been replacing the flame sensor every two months because it turns off the burners. Are they installing correctly or is this common? If not, what do you think is the problem? What can we do to prevent this?

Its not often a flame senser has to be replaced, they should take it out ,clean it (buff) lightly with very fine steel wool and put back,this can be done many times ,if its cleaned and then it doesn`t do right then replace. I`m not sure why the problem keeps reaccuring,I`ve never had the problems some people have ,over the years,I`ve installed several hundred goodman furnaces and don`t ever remember a flame senser problem