Abstract: A system for maintaining the heat of hot water circulating in hot water pipes. A generator mounted on the flue of a water heater converts exhaust heat from the water heater into electrical power, which is stored in a battery. The electrical power is used to power a circulating pump, which is activated when the temperature of the water in the hot water return pipe drops below a preset temperature; the circulating pump circulates through the water heater to keep it hot. In an alternative embodiment, the electrical power can be used to power heat tape, which has been applied to the outer surface of the hot water supply line in order to keep the water in the line hot. The system can be used with all gas-fired water heating systems, including tankless water heaters.

Abstract: An apparatus for venting several rooms having exhaust fans through existing roof openings made for existing ventilation systems, including turbine ventilators, roof ventilators, ridge ventilators and hip ventilators. The vent apparatus has two side panels, a bottom and two end panels. The apparatus is mounted under the roof ventilation system, using horizontal mounting elements disposed on the top edges of the end panels and side panels. When a ridge ventilator or hip ventilator is used, the end panels are formed with slots for fitting around the ridge rafter or hip rafter. The apparatus is mounted under the ridge ventilator, using mounting elements disposed along the slots on the end panels to attach the vent apparatus to the rafter. Each circular opening in the body had a stub extending downwardly for attachment of an end of the venting hose, which is connected to the bathroom exhaust vent fan. Removable covers can be placed into unused openings.

Abstract: An apparatus for venting several plumbing pipes through existing roof openings made for existing ventilation systems, including turbine ventilators, roof ventilators, ridge ventilators and hip ventilators. The plumbing vent apparatus has two sides, a bottom and two removable end caps. End caps for use with a ridge ventilator or hip ventilator have slots for fitting around the ridge rafter. The apparatus is mounted in the roof opening made for the ventilation system, which is installed above it. When used with a ventilation system which has a ridge or hip rafter, the apparatus can be configured to have mounting flanges along the top of the sides for attachment to the roof decking, or can have mounting flanges along the slots on the end caps for attachment to the rafter. Each male adapter, which is inserted through an opening in the bottom of the apparatus, can hold the venting end of a PVC plumbing pipe. Removable covers are placed into unused openings.

Abstract: A plumbing system which, when ambient outdoor temperatures drop below freezing, circulates water to prevent it from freezing, utilizing a check valve to prevent water from flowing back into the water main and further utilizing a relief valve which can open to the atmosphere and relieve pressure in the system if necessary. The system can have two separate circulation pumps, one for hot water and one for cold water.

Abstract: A backflow preventer assembly installed between a supply line and a service line, comprising one or more check valves and a high pressure relief valve operating to discharge water in the service line under a high pressure condition.