Evaporator case plenum air leaks separated To understand this item you may need to know some definitions. The evaporator case surrounds the evaporator coils (which is where air is cooled) and usually sits atop a heating unit but may be placed anywhere in the duct run. It appears to be a square metal box, and is usually wrapped with insulation. Air leaking from the evaporator case is not particularly serious but some efficiency is lost. A plenum, or plenum chamber, is a compartment or box in the duct system which usually precedes the individual duct runs. It's like a starting point for the ducting. A rooftop mounted unit generally has a large sheet metal elbow connected to one side of the unit. This may be considered a plenum in some cases. This particular type often pulls loose from the unit and may need tar or caulk to prevent air loss or rain entering the ducting. Both the evaporator case and plenum are under pressure when the system is running. Any leaks in either of these will usually be more forceful than leaks in an individual duct. The inspector will note this item if a considerable amount of air is being lost through gaps or holes in the case. Generally all that is needed to remedy the problem is duct tape or caulk applied over the leaking area to stop the air loss. Should you need assistance contact a handyman service or home repair service.
Leaks corrosion at convector radiator boiler circulating pump fittings: any leaks should be repaired immediately. Although the inspector may indicate a particular location for this situation be aware that others may exist. Have a qualified HVAC contractor completely review the heating system and make corrections as needed.