Mortise Lockset; Pellet Stove; Gas-Free Lawn Mowers Ask This Old House : Season 6 Episode 21

General contractor Tom Silva demonstrates how to install an old mortise lockset on a new door. Afterwards, plumbing and heating expert Richard Trethewey helps a homeowner install a pellet stove to provide supplemental heat during the cold winter months. Back in the loft, landscape contractor Roger Cook shows host Kevin O'Connor several different types of lawn mowers that do not require gasoline.