I have a ICG/Keeprite furnace #HCA090L, high efficiency, mfg 1984, input 90 btu, output 83.7 btu.
The furnace is natural gas has an electronic spark ignition and is still operating just fine but I am noticing a small puff of flame near the gas
nozzle/orifice during ignition making a popping sound, the flame lasts 2-3 seconds....the small flame and popping noise are only present when the pilot/ spark ignition clicks in (2-3 seconds)...disappears once main burner ignites....The gas nozzle/orifice is centered at the opening of the long 2
-3" dia. round burner shaft...There is only one main long burner with a cap spreader type of orifice on the
main flame end of the burner....I am suspecting the pipe dope around the gas nozzle/orifice has
dried up thru time...I will try to re-dope the fitting of the gas nozzle/orifice....I have been advised this could be a flashback symptom but also could this be a
pre-ignition/timing problem?....Any info, suggestions would be appreciated...thanks