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Installing an On-Demand Hot Water System

Bob talks with Dan Driscoll of Rinnai about the new on-demand water heater being installed. Driscoll explains that the heater is a whole-house system sized for a three-bathroom household, laundry, and cleaning. An on-demand, tankless water heater is energy efficient because it does not store hot water. Eliminating the tank also saves basement space. The unit can run three showers simultaneously with a flow rate of 5.3 gallons per minute and no drop in hot water delivery. The water heater has a moveable controller on the side so that the temperature of the hot water can be adjusted from anywhere in the home. Driscoll opens up the water heater to show how the system works. Once the water is turned on, sensors detect the amount of water being used and the temperature of the incoming cold water. The system adjusts the gas burner to meet the set temperature. Driscoll shows Bob the dual-chamber sealed-combustion PVC pipe that brings combustion air through the outside chamber and exhausts fumes through an inner tube. The on-demand system is about 40% more efficient than gas-fueled tank water heaters and 70% more efficient than electric tank water heaters. More information