Complete evaluation of the heating system and the air ducting system. Areas of concern: -37 year old heat exchanger is not certified due to the separations inside the heat exchanger clam shell welds (this may be a potential safety hazard to occupants inside the home during the heating cycle) (see attached photos) -Water has been coming through the evaporator pan into the blower and heat exchanger during the cooling cycle due to the 37 year old metal condensate pan inside the coil. (See attached photos) Air distribution system is original to home and is coming apart around the vapor barriers (see attached photos) System worked properly despite the potential safety hazards. Replaced 20x25x1 filter. Highly recommend replacing the system and converting to a heat pump since solar panels are installed on the roof and there is a federal tax credit up to $2000 this year from converting from natural gas heating to an all electric heat pump.