Miller Heating and Cooling Miller Heating and Cooling . Since 1919, Miller has been an integral part of improving the comfort of manufactured homes. Today, the manufactured home is a sophisticated, affordable home that is a smart choice for many buyers. Manuals & Parts - Miller Find replacement parts and get the most from your Miller products by downloading the specific Owner's Manual for your unit. From safety precautions, operations/setup information, and maintenance to troubleshooting and parts lists, Miller's manuals provide detailed answers to your product questions.