Suburban NT-12SE furnace - gas and spark, but no fire - why?

Old-Biscuit wrote:
Yes.......

The spark is happening too far away from gas flow to ignite the flame.

Bend the assembly down so that electrode is within 1/4-3/16" of slots and directly over that center group of slots. Also spark gap should be 1/8" from tip of electrode to the ground rod.

Yes, I had a similar problem with my refrigerator. I was surprised that if that spark isn't the right distance and in the right place it won't light. It was a big spark too. But, it has to be in the perfect place.