Get kids and animals out of house especially if anyone has a headache. Also open doors and windows to allow house to air out. Get a spray bottle and put a couple drops of soap (liquid dish soap) in bottle and fill with water. Go to all appliances that are ran off of gas, ie.-stove/oven,cloths dryer, water-heater,fireplace ( if gas supplied)wall furnaces etc... And slowly spray all flex pipes/valves etc... Leading to the appliance. Spray to entirely coat pipe, and look for bubbles.if no bubbles, then no leak. If you get bubbles, there's your leak. Turn off valve to app. And fix or call someone who can.
If it's to bad to do yourself, get out of house, turn off gas supply to house at meter. A pipe comes out of ground, goes to meter, then into wall. Valve is located between pipe out of ground and meter. Is usually little flat bar looking thing you can turn with crescent wrench. Turn so that bar layes horizontal on pipe to turn off.it'll never be easy to turn, so don't worry bout breaking it, they're all hard to turn. After that call a plumber. Good luck. P.S. But you may also want to check batteries in detector for charge also. Sean
If it's to bad to do yourself, get out of house, turn off gas supply to house at meter. A pipe comes out of ground, goes to meter, then into wall. Valve is located between pipe out of ground and meter. Is usually little flat bar looking thing you can turn with crescent wrench. Turn so that bar layes horizontal on pipe to turn off.it'll never be easy to turn, so don't worry bout breaking it, they're all hard to turn. After that call a plumber. Good luck. P.S. But you may also want to check batteries in detector for charge also. Sean