Upon arrival spoke with customer and he showed me where everything was. Started on furthest side working my way back and labeled all stats and units A-E. Found stats A and C failed, C was broken and A would randomly turn on and off. All other units are running. Customer approved replacement of stats. Put new stats on and made sure system came on. Went threw each unit and made sure they are clean and motors checked out within specs. All 5 systems are working well at this time and I showed customer. He was saying he’d like in the future to have us once a year go threw all heaters and heat pumps in the building, he will have it approved and let us know. Customer is happy at this time.