Empire furnace Model # GWT-35-2 seriel # 0614425864. I had a furnance repairman replace the to snap switch. Still have the same problem at times. Furnace will not start unless snap swich is pressed.
As an Empire Comfort Systems dealer, I'm not quite sure what your mean by "snap switch"?
It certainly isn't anything that's listed in the parts manual for your gravity vented furnace.
Your furnace is equipped with a manual "reset vent safety switch."
The manual reset vent safety switch will cause gas flow to the main
burner to "shut off" due to improper venting or a blocked flue.
Is this what your serviceman replaced? Since then have you or anyone checked to see is vent pipe is clogged or is improperly venting?
If the manual reset vent safety switch continues to "shut off" the gas
flow to the main burner. A qualified service person must be contacted
to inspect for improper venting, blockage in the vent pipe or the
manual reset vent safety switch for being defective.
Hope this helped to head you in right direction.