Performed clean and check on gas furnace and humidifier. Performed combustion analysis, tested all electrical components, inspected gas supply, drains, burner assembly, cleaned flame sensor, checked air filter and humidifier pad and measured temperature rise. Filter and humidifier pad are both in clean condition. Humidifier has a stuck solenoid. Needs replaced. System is otherwise operating normally at this time. Customer is interested in maintenance contract and wants humidifier repaired at a later date.