Performed heating maintenance on 5 year old Lennox air handler and heat pump. Cleaned return grates. Inspected and replaced filter with owner-supplied MERV 11 filter. Checked electrical draw of system and found it to be within limits. Inspected blower compartment and found blower wheel to be clean and balanced. Checked all electrical connections. Flushed condensate drain with water. Temperature rise is normal. Cleaned heat pump coil fins and exterior unit. Upon departure system is operational.