Disassembled the leaking Smith boiler and thoroughly cleaned and inspected all sections. Replaced the rear and one mid-section, then reassembled the complete boiler using new seals and gaskets throughout. During testing, the main system gate valve was found to be leaking and not holding pressure, so it was replaced to ensure proper system isolation. The boiler was then filled, fired, and fully tested to confirm proper operation and a tight, leak-free assembly.