Arrived on site to perform maintenance on 2 systems. On arrival found that the home has 4 systems. 3 units for the main house and 1 for the casita. Maintenance program is for 2 units only. After bringing it to homeowners attention he decided that he would like to add a third unit to the program. We will only be servicing the 3 units in the main home. Homeowner also mentioned that his unit in the back is not heating. Performed a diagnostic and found that limit switch was tripped because of a hammered filter. Reset switch, unit started heating. Advised to replace filter as soon as possible or it could happen again. Performed cooling maintenance on 3 units. Checked systems electrical and components. Refrigerant pressures are in range, systems cooling correctly. Pulled condenser fan motors and thoroughly washed all condensers inside and out. Went over recommendations with homeowner. Replaced secondary motor control for middle unit. System are operational upon departure.