Your first decision will be whether to buy a gas or electric model. Look beyond the price tag and the capacity when making a buying decision; check the yellow EnergyGuide label, your best tool for comparing models. On average, water heaters last for 13 years, so one that operates efficiently can pay you back in energy savings over time. On the label check the first-hour rating (FHR) number—this indicates how much hot water the heater can supply per hour at peak usage. The minimum FHR to select for your home will depend on the number of bathrooms and bedrooms it has.