Today I arrived on site Issue: Addressed the reported lack of heat on the 1st floor. Diagnosis: Found the 1st floor heating system was air bound. Resolution: Bleed all three zones to remove air from the lines. Current Status: Systems are now back up and running. Upon arriving at the property, the client explained to me that yesterday one of our technicians was doing some repairs. The customer says that the heat of the 1st floor is not heating. I proceeded to verify the Nest tstat, call for heat at the tstat. The system started to blow air. I immediately noticed that the system was blowing cold air. I proceeded to verify the AHU in the Basement. I found that the system had air in the lines. I showed him and explained the situation to the client. I proposed the lines bleed. I bled the x3 zones of the system. I concluded with the bleeding of the system. I started the system and monitoring for about 15-20 minutes. The system did not fail after the repair of this occasion. The