Performed heating maintenance on one heat pump system. Checked all electrical, mechanical and performance of the system. Customer supplied filter for replacement. I found that the system has a dirty blower wheel and also found small amounts of microbial growth in the air handler and on the evaporator coil. I presented the customer with options for repair but he declined repairs at this time. No other major issues were found, and the system is operational at this time. See attached checklist for full tune-up details.