Performed heating maintenance on two heat pump systems. Checked all electrical, mechanical and performance of both systems. Cleared and treated both drain lines and washed both outdoor condenser coils. I found small amounts of mold/mildew growth on the upstairs air handler at the evaporator coil and blower wheel. I presented options for repair to the customer, and he declined at this time. The downstairs system is low on refrigerant. I performed a leak search and was not able to find one at this time. The customer wants to replace the downstairs system and said he would give us a call when he’s ready for us to provide a quote. No other major issues were found, and both systems are on at this time.