Since most heating systems for smaller buildings are non-engineered, the installing contractor often has sole responsibility for ensuring that the components are properly matched, sized and installed. In the absence of proper training this can lead to the same mistakes being repeated over and over. It also leads to design stagnation, where installers are only willing to deal with certain types of equipment or system design, regardless of the situation with which they are faced.
Modern Hydronic Heating, 2nd Edition
Is this what you meant?