I posted this same issue in the bulletin boards as well. I got this response (pasted below this paragraph) from a fellow there, and my heater is an electric ignition heater. It does not use a gas pilot. So is this possible it is all it could be?
It is usually the same problem everyone with an electronic ignition has after not being serviced in the beginning of the year. The flame sensor most likely has to be cleaned. The tech will check all connections for tightness and cleanliness, the filter, the draft, and the gas pressure.