Reply #1: Any Idea What May Be Wrong?

[Sporadicus]

If it's a newer gas furnace, it may have a 'glow plug' type of ignitor. Check to see if there's a glass viewport near the combustion chamber. Cycle the furnace and see if the element glows red, like an electric stove element. If it doesn't, there's a good chance that the 'glow plug' has burned out.

Personally, I hate this system for starting a furnace cycle. The glow plugs are extremely sensitive to shock & vibration along with environmental substances. When replacing them, the servicer MUST NOT touch the heating element, lest residual finger oils remain on it, creating a hot spot when power is applied to the element, thereby causing premature failure. The elements are also sensitive to dryer lint and dust from cat-litter boxes; dryers & cat boxes are commonly located near furnaces :mad:

Give me the old-fashioned high-voltage spark ignition systems any day! I'd even sacrifice the loss of efficiency to have a small pilot flame going constantly in order to avoid the hassles of those GD glow plugs!

Although glow plugs may run in the $50-100 range, the servicer will likely tack on a hefty charge for the labor of replacing it. Perhaps you know a handy person who could perform the task for you?

I can empathize with your plight. Stay warm!