My house is heated by gas, but I'm an oil mechanic myself. I just went for a walk around the block and heard hissing from the exterior meter at a vacant house from thirty feet away. The house has undergone quite a bit of renovation recently, and National Grid has the meter locked. There's no smell of gas, or at least I didn't smell it after 14 hours of splashing around in ole #2. What could cause the hiss though?