Your HVAC and Furnace System

• Central air conditioners (HVAC) are often times tethered to a home's furnace. The system has several components including a compressor located outside the home and an evaporator located inside. The two are connected via copper supply lines. The evaporator is often located atop the furnace. This allows the blower from the furnace to perform double duty, blowing cold air in the summer and hot air in the winter. Neither the furnace or the HVAC system contains any water, but the HVAC system creates condensation as a byproduct of its operation. If there is a clear liquid leaking from the system, it is more than likely just water and is coming from your air conditioner. If the liquid is oily and located near the compressor you may have a refrigerant leak that will require professional attention.
  
  

Normal Condensation

• Condensation forms in two places on an HVAC system. The first is the supply line located at the base of the compressor and the second is within the evaporator. In both cases it is where warm air crosses the cold supply pipes. Outside, the pipe usually just gets "sweaty" but inside the evaporator pipes can create from 5 to 20 gallons of condensate daily. This condensation is drained away from the evaporator, usually to a ground location near the outdoor compressor. While water trickling out of the system may appear to be a problem, it is in fact an indication that the system is working correctly. If the condensation stops, they you have a cause for concern.
  
  

Water Leaks and Their Causes

• In addition to the primary drain, most HVAC systems have a secondary drain that terminates over a window or doorway. The placement of the drain is to catch your attention in the event water is diverted to the secondary drain. A common problem with the main drain is clogging due to mold and fungus growth. Clogs are easily removed with a shop vac or a pipe snake. Bleach poured into the drain system (1 cup a month) will help keep the pipes mold free and reduce the chance for mold growth. Other leaks can come from damage to the PVC drainage pipes due to being stepped on or crushed. Some homes do not have outdoor drainage and rely on a drain pan. If the pan has no means of drainage or the drain is clogged, it can overflow causing damage to the surroundings.
  
  

Calling in a Professional

• Crushed or damaged PVC pipes and drain cleaning can be fixed without professional help. If the system is showing signs of ice build up either on the copper supply lines or within the evaporator, the system is probably low on refrigerant. The formation of ice can block drains causing leakage. An HVAC professional is the only person qualified to add refrigerant to your system.