NAES Power Contractors (NPC) rebuilt an Alstom air preheater at an 850 MW coal-fired plant. NPC worked around the clock for three weeks to expedite the unit’s return to service. The team built temporary shelters to keep the major weather from impeding the work and coordinated with client representatives for support from the tool room, a local fabricator and ARVOS technical representative. This extensive rebuild included discovery of root cause as well as required repairs.