mark is an amazing individual. after calling National Grid, Petro inc., and 3 other technicians as i could only figure out how to make the blower functional for my Old Furnace before it completely stopped working. Mark did a great dianostic as he unlike like rest found the Main problem which was a fault gas valve. He then quickly dismantled and installed a new unit and Great duck work to give My home and family heat. Unlike the rest wasnt trying to just take my money in a needed situation by telling lies about parts that didnt need to be fixed.Mark is a real pros pro. Great detail in his work got the job done in a day once he got the supplies. trust me when i say YOUR BE GLAD you choose MAZGAN.