An early wakeup for crews from Royersford and Trappe this morning being alerted to a fire alarm on Buckwalter Road at 5:30am. Shortly after dispatch the assignment was upgraded from a fire alarm to a building investigation after the reports were received the homeowners smelled something inside the residence, the upgraded assignment added an engine from Liberty Fire Company in Spring City. Crews arrived and after investigating determined the root cause was a faulty detector which was past its useable time period. Crews cleared returning to their respective stations to warm up after being out in the sub-freezing temperatures.