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"To gas or not to gas? The Home Depot tackles everything you always wanted to know about the different types of energy-saving water heaters (but were afraid to ask)."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/your-home/at-home/blogs/water-heaters-101-how-to-choose-the-most-efficient-model-infographic>