Returned to install new iComfort S30 thermostat under warranty and perform heating maintenance on 7 year old Lennox air handler and heat pump. Installed new iComfort S30 thermostat. Indoor Unit: Cleaned return grate. Flushed condensate drain with water. Measured total amp draw and found it to be within limits. Inspected blower compartment and found blower wheel to be clean and balanced. Inspected electrical connections. Tested in both cooling and heating, temperature rise is normal. Outdoor Unit: Removed heat pump covers and cleaned coil fins as well as around exterior unit. Replaced covers. Upon departure the system is operational but turned off at the thermostat because there is not filter installed.