The fire box is lighting but the furnace fan doesn't come on. Where is the temp relay? I've got a York Stellar Plus, Model P1UDD12N09501A with a Honeywell Chronotherm 3 stat.
I assume the whole circuit is in the furnace itself BUT it could be in the stat as well. I know I can turn the furnace fan hard on at the thermostat. Maybe the York return a firebox temperature signal to the C3.
Thanks