Completed 2 system maintenance on 17 year old units. Blowers are dirty coils have rust and corrosion on them. Neither has back up water safety to protect furnace from water damage. Upstairs has UV light attached. Downstairs need UV light for whole house purification. Changed filters. Drain lines are clear. Outdoor units have good pressures running on r22 Freon which is phased out. Capacitors are good. Systems missing compressor saver to take load off compressor during start up and allow compressor to live longer.