Plot: Host Kevin O'Connor and plumbing and heating expert Richard Trethewey head to Virginia to help a homeowner replace his old, electric water heater with a heat pump water heater that uses much less electricity. Then, up in the loft, Richard and Kevin, along with general contractor Tom Silva and landscaping contractor Roger Cook ask, "What is it?" Afterward, Roger and Kevin discuss propane-fueled mosquito traps and how to keep them working properly