Arrived on site to perform maintenance on 2 12 year old systems. Cycled furnaces for heat. Checked indoor units electrical and system components. Blew off insulation off of platform, as well as blew off all dust on furnaces and inside heat and blower compartments. Flame sensors are both clean. Blower wheels have slight dust build up on them. Both blower motors are leaking quite a bit of oil and working hard. Temperature rise on both units is within allowed range. Static pressures are above allowed range. Replaced all 1 inch filters. Condensation lines do not have any condensation switches and secondary port on both units just drains right into the drain pan. Downstairs pressure switch is having trouble closing some time and will not allow furnace to start, pressure switch should be replaced. Went over findings and recommendations with homeowner. Discussed the importance of having heat exchanger thoroughly checked and inspected. Went over findings and recommendations. Homeowners are ha