Merrimack, NH Sept 27- Merrimack firefighters received a call from a homeowner that the house was on fire early Tuesday evening. Firefighters were dispatched ay 19:10 hrs and as they approached the area, they could see heavy smoke and transmitted the working fire. First due companies soon arrived to find a garage and two vehicles outside fully involved. Firefighters stretched hose lines to the interior of the house and conducted primary searches. Command then requested a second-alarm to bring in more manpower and Nashua's Ladder to vent the roof. Firefighters also had challenges with water supply and hose lines were brought to the scene from hydrants a significant distance away. The fire extended to the house and caused heavy smoke and water damage. The fire is under investigation and there were no reported injuries.