Completed 2 system maintenance. Upstairs system is 4 years old with clean blower clogged drain line. Clean evap coil and very dirty filter in one of the 3 returns. Other returns had no filter and no filter at system. Took small filter out of return and added filter at the system to filtrate all 3 returns. Cleared drain line. System has no water safety. Added inline float switch. System would benefit from having UV light installed to kill and bacteria viruses or allergens that could cause harm to reseidents. Downstairs system is 6 years old with clean blower and coil. Has clogged drain line and no filter. Added filter at system. Cleared drain line system also has no water safety. Installed inline float switch. System would also benefit from UV light installed. Outdoor unit has good pressures and working electrical components. Systems would benefit from having compressor savers installed to take load off compressor during start up and allow compressor to live longer.