Hi folks! When i lit the ceramic burner it burn a nice red glowing ceramic and burn silent. When the burner are in the furnace, there is problem where noise came from burner after some minutes silent burning. There is hot exhaust from chimney with silent burning, after some minutes suddenly it came noise from burner and a bit smoke from chimney + weak hot. Is it common problem in Stuart boiler HB4 with ceramic burner without secondar air? The jet is number 8 who followed with the set of boiler/burner.