I appreciate the quick response - I know that the filter must be changed frequently. However, it was working fine before the filter was changed initially, so I want to eliminate the possibility that there was another cause. I will change the filter and if it runs properly for 24 hours I will give your response a positive rating.
It seems after four days of working correctly with the new filter in place, my furnace shut off again this afternoon. Is there any other simple maintenance I can try in order to get it working again? I know that it CAN work properly, so perhaps there is something else dusty or dirty that I can clean to get it working?
Are there any videos available that could assist me in cleaning the blower wheel?