Looking for fault finding help from some one who has detailed knowledge of Burley 4121 faults, burner unit is over 5years old and has been cleaned out regularly, pilot flame is o.k. And all bets are clear. Burner unit generally looks o.k
However the flame is very low and does not increase in height, or change colour as it does when working normally. This is the second burner unit that has been fitted suggesting it might need a new burner.