Plumbing and heating expert Richard Trethewey and a water specialist examine a homeowner's water quality and discuss the installation of a water softener and sediment filter. Back at the loft, Richard, general contractor Tom Silva, landscape contract... (more)or Roger Cook, and host Kevin O'Connor try to guess "What is it?" Then Tom makes a House call to help a homeowner replace a rotten board in her oak hardwood flooring.