- Less Can Be More With one of most compact cabinets in the industry (33-inches high) this unit requires less space outside and provides more heating capacity inside. - Good Housekeeping Seal This model is proud to have earned the Good Housekeeping Seal a nearly century-old symbol of quality and trust. - 10-Year Limited Parts and Lifetime Heat Exchanger Warranties This product is covered by some of the best warranties in the business: 10-year limited parts and lifetime heat exchanger warranties. - ENERGY STAR The ENERGY STAR label means this product is at least 15 to 25% more efficient than standard products, meeting strict EPA and DOE guidelines.