I am at work, But I will see if I have some pics of the plumbing in my photobucket. Yes, the furnace is gas. It is located about 8 feet from the sump. It is a 95 plus furnace, and uses a PVC exhaust. There is another PVC "port" on the furnace that is for fresh air, that is supposed to be plumbed outside to bring in fresh air to the house, but the installers never ran it outside, so basically, the furnace is only re-circulating te air already in the house. I have never had the basement checked for methane levels. Lemme see what I can dig out of the photobucket....:
Jason