Performed heat maintenance on 6 year old carrier gas/electric roof package unit. System was tripped on high limit due to high gas pressure when I arrived. Adjusted gas pressure back down to manufactures specs. Cleaned all furnace components. Tightened all electrical connections. Performed safety inspection, no breaches found. Contactor is burnt and pitted, recommend replacing. Tenant has asthma and other respiratory issues, recommend adding an Iwave air purifier for better indoor air quality. System is operational and heating at this time