How to increase air supply to Riello RDB Burner?

when you say smoke, is it white or black?
if its white, this is correct and is condensing steam.
if its black, the combustion settings are way off and need a qualified oftec service engineer to set the burner up with a flue gas analser.
the air screw is on the right hand side of burner, a 3mm allen screw,
but if you twiddle this without the correct training and equipment you will risk melting the blast tube and rendering the boiler scrap.

mark
February 2013