Bob talks with factory representative Chris Hoff and heating contractor Peter Lydon during the installation of a Buderus high-efficiency boiler. They note several features that improve the unit's efficiency, including stainless-steel burner tube, insulated jacket and sophisticated Honeywell controls.

Bob visit the Buderus boiler manufacturing plant with Chris Hoff to see how the house and water heater is made.

Bob meets Jack O'Leary, the plumbing and heating contractor for this remodeling project. They discuss the old heating unit, which was an oil-fired steam system that used radiators throughout the house. The house has doubled in size since adding a new addition, and the old unit can't handle the new load. It was too costly to add another steam unit, so they decided to go with an oil-fired boiler. This works well for the homeowner, since oil is cheaper than electric, and gas isn't available in the area.

Bob visits with Mark Lundquist of Burnham Hydronics to check out the boiler for the hot-water heating system being installed in the Mashpee, Massachusetts, affordable homes. This Burnham Spirit model is a medium efficiency, easy-to-maintain, sealed-combustion unit. Since it is sealed combustion, it pulls the air it needs directly from the outdoors and vents to the exterior without the use of a chimney or flue. This enables a homeowner to close off the space surrounding the boiler without worrying about available combustion air for the furnace. This model uses standard parts, so any repairs will be fast and easy. The boiler is made of cast iron and has a 25 to 40 year life expectancy. It operates at 84 percent efficiency, so the homeowner will use energy dollars wisely. Charlie Delvecchio of Cape Plumbing breaks out the cost of the boiler to about $1,500 and the baseboard tubing for another $6,000, for a total cost of $7,500 for installation of the home heating system. The domestic hot-water tank is linked to the heating system as hot water from the boiler passes through a coil in the insulated hot-water tank, warming the household water through energy exchange. If the water is maintained at the proper temperature just from this passive exchange, the boiler will never be called upon to heat water for faucets and showers.

Back at the Cobb Hill co-housing community, Bob meets up with builder Kevin O'Hara who shows Bob the enormous Garn wood gasifying boiler that has just arrived. The boiler heats hot water by burning the particulate in a second chamber after the wood has been burned. The hot water will be sent throughout the co-housing for heat. Community members will manually feed the lumber which will be harvested right on the property as fuel for the boiler. The individual residences will be tied together with Ecoflex insulated underground pipe that runs throughout the project. Each pod (there are three in the community) will have its own backup gas boiler for when the temperature really drops.

A high-efficiency Buderus boiler is installed in the Roxbury, Mass., house. Steve Offutt from the U.S. Environmental Protection Agency describes the Energy Star Program for high-efficiency heating and cooling equipment, kitchen appliances, and office equipments. The program strives to save energy and reduce pollution from homes. The average home pollutes more than the average car.

The PEX tubing is set in the concrete and will circulate hot water used to heat the addition. Jason McKinnon of Viega North America reviews the features of PEX tubing. PEX is electronically cross-linked polyethylene tubing that is made to be stronger and resistant to high temperatures and pressures. The PEX tubing was placed in the concrete slab. The concrete acts a low-temperature radiator for the tubing. High temperature water will be pumped through the coils and heat will dissipate into the slab. A heated slab acts as a radiant heat source for the home. Tim Cutler of TJ's Plumbing & Heating reviews how the tubing was placed within the slab. In a radiant-heat application, the tubing is evenly spread out across the floor. With radiant heat, the air is not heated, only the floor. The heat is modulated according to outside weather conditions so a precise amount of heat is sent through the coils to warm the building's interior to the desired temperature. A heat/loss analysis done on the home indicates that the tubing should have nine-inch spacing for five circuits. During manufacturing, the tubing has 10,000 volts sent through it which cause the molecules to cross-link. This makes the tubing virtually indestructible. An oxygen barrier is sprayed on it to protect the boiler and the heating system from oxygen infiltration, which causes cast iron boilers to deteriorate. A foam stapler pushes plastic clips with prongs into the foam decking to secure the tubing in place.

Bob Berle shows Bob Vila the bowels of the home and points out the decay that was prevalent but currently under repair. The 35,000 square foot basement was open to the elements prior to the Berles� arrival and during the winter was buried in four feet of snow. Deep in the past a small town atmosphere existed in the basement, with a launderer, a butcher, and a baker to serve the Vanderbilts and their guests. At one point in time, over 120 people were seasonally employed by the house to maintain the grounds and serve the guests. Due to years of neglect and changing expectations, the entire communications and electrical systems in the house needed to be replaced using suspended channels for low voltage and commercial pipes for high voltage wiring. Even with the home�s immense size residential heating systems will be employed using nine boilers, which allow for individual zones for every one of the 109 rooms. To prevent fire, the boiler room is practically airtight and the boiler�s heating elements are vented directly outdoors, with an electronically controlled air induction system

Bob joins Steve Bottazzi, a plumbing contractor, who is taking out an old boiler system and installing a new state-of-the-art system. The new system at 280,000 BTU is three times the strength of the old boiler and is smaller in size. It also serves as the heater for the household hot water tank. Steve shows Bob how he adds the manifold on each side of the boiler to direct the flow to the four zones in the original and new sections of the home. He also gives Bob a lesson on threading pipe.

John Marran of Energy Kinetics and heating expert Frank Iadarola review the System 2000 boiler system that will supply heat to the hydronic floors and units at either end of the garage. The sytem has various stages to allow for quick heat and controllers to monitor the temperature of the hydronic fluid. The System 2000 contains only 2.5 gallons of water. Since it only takes approximately 1 and a half minutes to heat up that small amount of water, there is no need for the water to be heated all the time. The boiler is activated only when you need heat or hot water. After it supplies the heat or hot water the boiler does not remain hot. This saves a lot of energy.