I will be doing some repiping in the basement sometime in the future. I would like to relocate the HW heater to the other end of the house. In reality this proposed location would be the shortest distance to all hot water sources and was probably only located at the other end of house due to a chimney for upstairs fireplace. I would like to install a 40 gal gas heater next to an outside block wall. The top 2' of wall is above ground level outside. I have no problem moving gas and water connections but am not sure of what is needed for venting the heater. Do I use some kind of lined pipe through the wall and up the side of the house? Does this have to go above the roof-line? Is there a way of venting without going all the way to the roof? I did not buy my new heater yet since I wanted to investigate all options first. Any thoughts would be appreciated. Thanks