I have a Vokera excel 80 boiler approx 8 years old. Where i live is quite exposed and the wind passing the flue outlet is blowing the main burner out. The boiler then has to fire the burners up again, this cycle can happen 5 or 6 times a minute. Is there any thing i can fix to my wall to divert the wind around the outlet. I understand that I cannot cover it.