At ~12:47 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) for a Carbon Monoxide (CO) Alarm at a home on Lyons Run Road. Station 20 responded with Engine 20 (4 firefighters), with 5 firefighters (including Assistant Chief 20 and Captain 20) on station standby with in case additional resources were needed at the scene, and 1 firefighter responding directly to the scene. The direct responding firefighter was first on scene, established the command, and ensured that the home was evacuated. Engine 20 arrived on scene, itscrew entered the structure, and surveyed the interior with 4-Gas Meters. No evidence of CO was found, the home ventilated, and the homeowner was going to contact their alarm company. Command 20 returned Engine 20 to service and station.