Ask This Old House S04 E20 Granite Driveway Marker; Hot Water Radiator System

Landscaping contractor Roger Cook and a specialist help a homeowner install a granite driveway marker so that visitors can more easily find his house. Then Roger, along with plumbing and heating expert Richard Trethewey, general contractor Tom Silva, and host Kevin O'Connor ask, "What is it?" Afterward, Richard heads to Pennsylvania to fix a hot water radiator that is not providing any heat.