Place a smoke bomb or furnace candle within the firebox. Gas lines Check for leaks. Painting soapy water on the joints and seams. Exhaust chimney Check for leaks and obstructions. Pilot light Clean pilot and orifice.
Flame Make sure the burner flame is clear blue.
Yellow or orange flames represent impurities or a wrong setting. If you suspect ethylene injury is occurring, contact your local MSU Extension floriculture agent. We can look at the crop and obtain air samples to verify if ethylene is the problem. Also call your furnace maintenance firm to inspect the unit in question. Most plants will recover from ethylene injury.