need them. Reduced emissions, low fuel utilization and a reduced carbon footprint give Nexus our green stamp of approval! This technology automatically varies discharge temperatures based on the outside air temperature. With efficiencies up to 97%, the Effinity is the most efficient gas unit heater in North America. efficient and accurate model on the market! Units will maintain clean combustion in a partial blockage situation without decreasing performance insuring safe combustion at all times. No material from this site may be copied, distributed or in any way used without expressed prior permission. 2023 Reznor HVAC, This website is intended for North American customers only. Siemens to build large CO2-free hydrogen production plant in Bavaria Learn about our energy efficient innovations that can help you save on your heating & cooling energy expenses, while ensuring your home is comfortable. Sterling's Nexus Unit Heater Series boast unmatched levels of unit heater efficiency. Units are ready for standard or separate combustion all in one unit. There's No Need To Worry!\"}]},{\"URL\":\"heating\\\/infrared-heaters.html\",\"Parent\":\"322\",\"displayText\":\"Infrared Heaters\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/infrared-tube-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-infrared-15-1.jpg\",\"displayText\":\"Infrared Tube Heaters\"},{\"URL\":\"heating\\\/high-intensity-infrared-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-infrared-15-2.jpg\",\"displayText\":\"High Intensity Infrared Heaters\"},{\"URL\":\"heating\\\/infrared-patio-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-infrared-15-3.jpg\",\"displayText\":\"Patio Heaters\"},{\"URL\":\"heating\\\/infrared-patio-heater-components.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-infrared-15-4.jpg\",\"displayText\":\"Patio Heater Components\"},{\"URL\":\"heating\\\/infrared-heater-accessories.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-infrared-15-5.jpg\",\"displayText\":\"Infrared Heater Accessories\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/infrasave-infrared-heaters.html\",\"displayText\":\"InfraSave\"},{\"URL\":\"heating\\\/reznor-infrared-heaters.html\",\"displayText\":\"Reznor\"},{\"URL\":\"heating\\\/modine-infrared-heaters.html\",\"displayText\":\"Modine\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Categories\",\"linkItems\":[{\"URL\":\"heating\\\/complete-infrared-tube-heaters.html\",\"displayText\":\"Complete Tube Heaters\"},{\"URL\":\"heating\\\/high-intensity-infrared-heaters.html\",\"displayText\":\"High Intensity Infrared Heaters\"},{\"URL\":\"heating\\\/infrared-tube-kits.html\",\"displayText\":\"Tube Kits\"},{\"URL\":\"heating\\\/infrared-tube-heater-burners.html\",\"displayText\":\"Burners\"}]},{\"URL\":\"stories\\\/1157-Three-Ways-to-Heat-Your-Garage.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_1157.jpg\",\"linkItems\":[],\"displayText\":\"Too Cold to Use Your Garage?\"}]},{\"URL\":\"heating\\\/hydro-air.html\",\"Parent\":\"322\",\"displayText\":\"Hydro Air\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/hydronic-air-handlers.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-hydro-15-1.jpg\",\"displayText\":\"Hydronic Air Handlers\"},{\"URL\":\"heating\\\/hot-water-coils.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-hydro-15-2.jpg\",\"displayText\":\"Hot Water Coils\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/weil-mclain-hydronic-air-handlers.html\",\"displayText\":\"Weil-McLain\"}]}]},{\"URL\":\"heating\\\/electric-warm-air.html\",\"Parent\":\"322\",\"displayText\":\"Electric Warm Air\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/electric-furnaces.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-electric-15-1.jpg\",\"displayText\":\"Electric Furnaces\"},{\"URL\":\"heating\\\/plenum-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-electric-15-2.jpg\",\"displayText\":\"Plenum Heaters\"},{\"URL\":\"heating\\\/duct-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-electric-15-3.jpg\",\"displayText\":\"Duct Heaters\"},{\"URL\":\"heating\\\/electric-heat-controls.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-electric-15-4.jpg\",\"displayText\":\"Electric Heat Controls\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/revolv-electric-furnaces.html\",\"displayText\":\"Revolv\"},{\"URL\":\"heating\\\/electro-industries-plenum-heaters.html\",\"displayText\":\"Electro Industries\"},{\"URL\":\"heating\\\/williams-electric-furnaces.html\",\"displayText\":\"Williams\"}]}]},{\"URL\":\"heating\\\/heating-controls.html\",\"Parent\":\"322\",\"displayText\":\"Heating Controls\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"thermostats\\\/thermostats.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-1.jpg\",\"displayText\":\"Thermostats\"},{\"URL\":\"thermostats\\\/forced-air-zone-controllers.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-2.jpg\",\"displayText\":\"Zone Controllers\"},{\"URL\":\"heating\\\/gas-valves.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-3.jpg\",\"displayText\":\"Gas Valves\"},{\"URL\":\"heating\\\/ignition-controls.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-4.jpg\",\"displayText\":\"Ignition Controls\"},{\"URL\":\"heating\\\/ignitors.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-5.jpg\",\"displayText\":\"Ignitors\"},{\"URL\":\"heating\\\/thermocouples.html\",\"imageURL\":\"nav-image\\\/100\\\/heat-control-15-6.jpg\",\"displayText\":\"Thermocouples\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"thermostats\\\/nest-thermostats.html\",\"displayText\":\"Nest\"},{\"URL\":\"thermostats\\\/ecobee-thermostats.html\",\"displayText\":\"Ecobee\"},{\"URL\":\"thermostats\\\/honeywell-thermostats.html\",\"displayText\":\"Honeywell\"},{\"URL\":\"thermostats\\\/white-rodgers-thermostats.html\",\"displayText\":\"White Rodgers\"},{\"URL\":\"thermostats\\\/aprilaire-thermostats.html\",\"displayText\":\"Aprilaire\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Categories\",\"linkItems\":[{\"URL\":\"thermostats\\\/smart-thermostats.html\",\"displayText\":\"Smart Thermostats\"},{\"URL\":\"thermostats\\\/wifi-thermostats.html\",\"displayText\":\"Wi-Fi Thermostats\"},{\"URL\":\"thermostats\\\/programmable-thermostats.html\",\"displayText\":\"Programmable Thermostats\"},{\"URL\":\"thermostats\\\/basic-thermostats.html\",\"displayText\":\"Basic Thermostats\"},{\"URL\":\"thermostats\\\/thermostat-accessories.html\",\"displayText\":\"Thermostat Accessories\"}]},{\"URL\":\"stories\\\/1139-How-to-Pick-the-Perfect-Thermostat.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_1139.jpg\",\"linkItems\":[],\"displayText\":\"Thermostat Buying Guide\"}]}]},{\"URL\":\"heating\\\/boilers.html\",\"displayText\":\"Boilers\",\"subNavigationLinks\":[{\"URL\":\"heating\\\/gas-fired-boilers.html\",\"Parent\":\"334\",\"displayText\":\"Gas Boilers\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/natural-gas-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/nattygas_9b500f1d1f1cb17c4678a38fb6a157b8.jpg\",\"displayText\":\"Natural Gas\"},{\"URL\":\"heating\\\/liquid-propane-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-gas-15-2.jpg\",\"displayText\":\"Propane\"},{\"URL\":\"heating\\\/gas-fired-hot-water-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-gas-15-3.jpg\",\"displayText\":\"Gas Hot Water\"},{\"URL\":\"heating\\\/gas-fired-steam-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-gas-15-4.jpg\",\"displayText\":\"Gas Steam\"},{\"URL\":\"heating\\\/standard-efficiency-gas-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-gas-15-5.jpg\",\"displayText\":\"Standard Efficiency\"},{\"URL\":\"heating\\\/high-efficiency-gas-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-gas-15-6.jpg\",\"displayText\":\"High Efficiency\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/weil-mclain-gas-fired-boilers.html\",\"displayText\":\"Weil-McLain\"},{\"URL\":\"heating\\\/burnham-gas-boilers.html\",\"displayText\":\"Burnham\"},{\"URL\":\"heating\\\/buderus-gas-boilers.html\",\"displayText\":\"Buderus\"},{\"URL\":\"heating\\\/crown-boiler-gas-boilers.html\",\"displayText\":\"Crown Boiler\"},{\"URL\":\"heating\\\/proselect-boilers.html\",\"displayText\":\"ProSelect Force Boilers\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Shop by Vent Type\",\"linkItems\":[{\"URL\":\"heating\\\/direct-vent-gas-boilers.html\",\"displayText\":\"Direct Vent\"},{\"URL\":\"heating\\\/chimney-vent-gas-boilers.html\",\"displayText\":\"Chimney Vent\"},{\"URL\":\"heating\\\/power-vent-boilers.html\",\"displayText\":\"Power Vent\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Shop by Feature\",\"linkItems\":[{\"URL\":\"heating\\\/combi-dual-purpose-boilers.html\",\"displayText\":\"Combi\"},{\"URL\":\"heating\\\/condensing-gas-boilers.html\",\"displayText\":\"Condensing\"},{\"URL\":\"heating\\\/modulating-gas-boilers.html\",\"displayText\":\"Modulating\"}]},{\"URL\":\"stories\\\/438-How-to-Pick-the-Perfect-Boiler.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_438.jpg\",\"linkItems\":[],\"displayText\":\"Boiler Buying Guide\"}]},{\"URL\":\"heating\\\/oil-boilers.html\",\"Parent\":\"334\",\"displayText\":\"Oil Boilers\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/oil-fired-hot-water-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/hotwatieroiler_574dfad261986acae55a2d367d1b7843.jpg\",\"displayText\":\"Hot Water Oil\"},{\"URL\":\"heating\\\/oil-fired-steam-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-oil-15-2.jpg\",\"displayText\":\"Steam Oil\"},{\"URL\":\"heating\\\/cast-iron-oil-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-oil-15-3.jpg\",\"displayText\":\"Cast Iron\"},{\"URL\":\"heating\\\/condensing-oil-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-oil-15-4.jpg\",\"displayText\":\"Condensing\"},{\"URL\":\"heating\\\/high-efficiency-oil-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-oil-15-5.jpg\",\"displayText\":\"High Efficiency\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/weil-mclain-oil-fired-boilers.html\",\"displayText\":\"Weil-McLain\"},{\"URL\":\"heating\\\/burnham-oil-fired-boilers.html\",\"displayText\":\"Burnham\"},{\"URL\":\"heating\\\/buderus-oil-fired-boilers.html\",\"displayText\":\"Buderus\"},{\"URL\":\"heating\\\/proselect-force-oil-boilers.html\",\"displayText\":\"ProSelect Force\"},{\"URL\":\"heating\\\/williamson-thermoflo-oil-fired-boilers.html\",\"displayText\":\"Williamson-Thermoflo\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Shop by Vent Type\",\"linkItems\":[{\"URL\":\"heating\\\/chimney-vent-oil-fired-boilers.html\",\"displayText\":\"Chimney Vent\"},{\"URL\":\"heating\\\/direct-vent-oil-fired-boilers.html\",\"displayText\":\"Direct Vent\"}]},{\"URL\":\"stories\\\/1168-A-Break-Down-of-Boiler-Fuel-Options.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_1168.jpg\",\"linkItems\":[],\"displayText\":\"Which Boiler Fuel Should I Use?\"}]},{\"URL\":\"heating\\\/electric-boilers.html\",\"Parent\":\"334\",\"displayText\":\"Electric Boilers\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/120-volt-1-phase-electric-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-electric-15-1.jpg\",\"displayText\":\"120 Volt\\\/1 Phase\"},{\"URL\":\"heating\\\/208-volt-3-phase-electric-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-electric-15-2.jpg\",\"displayText\":\"208 Volt\\\/3 Phase\"},{\"URL\":\"heating\\\/240-volt-1-phase-electric-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-electric-15-3.jpg\",\"displayText\":\"240 Volt\\\/1 Phase\"},{\"URL\":\"heating\\\/240-volt-3-phase-electric-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-electric-15-4.jpg\",\"displayText\":\"240 Volt\\\/3 Phase\"},{\"URL\":\"heating\\\/480-volt-3-phase-electric-boilers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-electric-15-5.jpg\",\"displayText\":\"480 Volt\\\/3 Phase\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"heating\\\/electro-industries-boilers.html\",\"displayText\":\"Electro Industries\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Shop by Capacity\",\"linkItems\":[{\"URL\":\"heating\\\/less-than-50000-btu-electric-boilers.html\",\"displayText\":\"< 50,000 BTU\"},{\"URL\":\"heating\\\/50000-100000-btu-electric-boilers.html\",\"displayText\":\"50,000 - 100,000 BTU\"},{\"URL\":\"heating\\\/100000-250000-btu-electric-boilers.html\",\"displayText\":\"100,000 - 250,000 BTU\"},{\"URL\":\"heating\\\/250000-500000-btu-electric-boilers.html\",\"displayText\":\"250,000 - 500,000 BTU\"},{\"URL\":\"heating\\\/greater-than-500000-btu-electric-boilers.html\",\"displayText\":\"> 500,000 BTU\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Shop by Type\",\"linkItems\":[{\"URL\":\"heating\\\/modulating-electric-boilers.html\",\"displayText\":\"Modulating\"},{\"URL\":\"heating\\\/electric-boiler-accessories.html\",\"displayText\":\"Accessories\"},{\"URL\":\"heating\\\/staging-electric-boilers.html\",\"displayText\":\"Staging\"}]},{\"URL\":\"stories\\\/438-How-to-Pick-the-Perfect-Boiler.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_438.jpg\",\"linkItems\":[],\"displayText\":\"Boiler Buying Guide\"}]},{\"URL\":\"heating\\\/boiler-accessories.html\",\"Parent\":\"334\",\"displayText\":\"Boiler Accessories\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"heating\\\/zoning-circulation.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-acc-15-1.jpg\",\"displayText\":\"Zoning & Circulation\"},{\"URL\":\"heating\\\/boiler-trim.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-acc-15-2.jpg\",\"displayText\":\"Boiler Trim\"},{\"URL\":\"thermostats\\\/boiler-controls.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-acc-15-3.jpg\",\"displayText\":\"Boiler Controls\"},{\"URL\":\"heating\\\/heat-exchangers.html\",\"imageURL\":\"nav-image\\\/100\\\/boiler-acc-15-4.jpg\",\"displayText\":\"Heat Exchangers\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Zoning and Circulation\",\"linkItems\":[{\"URL\":\"heating\\\/circulation-pumps.html\",\"displayText\":\"Circulation Pumps\"},{\"URL\":\"heating\\\/boiler-zone-control.html\",\"displayText\":\"Zone Control\"},{\"URL\":\"heating\\\/mixing-materials.html\",\"displayText\":\"Mixing Materials\"},{\"URL\":\"heating\\\/flow-control-materials.html\",\"displayText\":\"Flow Control Materials\"},{\"URL\":\"heating\\\/pump-parts-and-accessories.html\",\"displayText\":\"Pump Parts & Accessories\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Boiler Trim\",\"linkItems\":[{\"URL\":\"heating\\\/boiler-trim-packages.html\",\"displayText\":\"Boiler Trim Packages\"},{\"URL\":\"heating\\\/expansion-tanks.html\",\"displayText\":\"Expansion Tanks\"},{\"URL\":\"heating\\\/air-separators.html\",\"displayText\":\"Air Separators\"},{\"URL\":\"heating\\\/dirt-separators.html\",\"displayText\":\"Dirt Separators\"},{\"URL\":\"heating\\\/water-feeders-feed-valves.html\",\"displayText\":\"Water Feeders & Feed Valves\"}]},{\"URL\":null,\"type\":\"list\",\"title\":\"Boiler Controls\",\"linkItems\":[{\"URL\":\"thermostats\\\/aquastats.html\",\"displayText\":\"Aquastats\"},{\"URL\":\"thermostats\\\/boiler-control-accessories.html\",\"displayText\":\"Boiler Control Accessories\"},{\"URL\":\"thermostats\\\/reset-controls.html\",\"displayText\":\"Reset Controls\"},{\"URL\":\"heating\\\/sensors-control-accessories.html\",\"displayText\":\"Sensors & Control Accessories\"},{\"URL\":\"thermostats\\\/staging-modulating-controls.html\",\"displayText\":\"Staging & Modulating Controls\"}]},{\"URL\":\"stories\\\/203-Hydronic-System-Accessory-Guide.html\",\"type\":\"image\",\"title\":\"Buyer's Guide\",\"imageURL\":\"nav-article-image\\\/305\\\/social_img_203.jpg\",\"linkItems\":[],\"displayText\":\"What Goes With My Boiler?\"}]}]},{\"URL\":\"water-heaters\\\/water-heaters.html\",\"displayText\":\"Water Heaters\",\"subNavigationLinks\":[{\"URL\":\"water-heaters\\\/tankless-water-heaters.html\",\"Parent\":\"339\",\"displayText\":\"Tankless Water Heaters\",\"sectionLinks\":{\"columns\":\"6\",\"linkItems\":[{\"URL\":\"water-heaters\\\/gas-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-1.jpg\",\"displayText\":\"Gas\"},{\"URL\":\"water-heaters\\\/electric-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-2.jpg\",\"displayText\":\"Electric\"},{\"URL\":\"water-heaters\\\/natural-gas-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-3.jpg\",\"displayText\":\"Natural Gas\"},{\"URL\":\"water-heaters\\\/lp-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-4.jpg\",\"displayText\":\"Liquid Propane\"},{\"URL\":\"water-heaters\\\/whole-house-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-5.jpg\",\"displayText\":\"Whole House\"},{\"URL\":\"water-heaters\\\/point-of-use-tankless-water-heaters.html\",\"imageURL\":\"nav-image\\\/100\\\/water-tankless-15-6.jpg\",\"displayText\":\"Point-of-Use\"}]},\"subCategories\":[{\"URL\":null,\"type\":\"list\",\"title\":\"Popular Brands\",\"linkItems\":[{\"URL\":\"water-heaters\\\/takagi-tankless-water-heaters.html\",\"displayText\":\"Takagi\"},{\"URL\":\"water-heaters\\\/rinnai-tankless-water-heaters.html\",\"displayText\":\"Rinnai\"},{\"URL\":\"water-heaters\\\/noritz-tankless-water-heaters.html\",\"displayText\":\"Noritz\"},{\"URL\":\"water-heaters\\\/rheem-tankless-water-heaters.html\",\"displayText\":\"Rheem Tankless\"},{\"URL\":\"water-heaters\\\/ao-smith-tankless-water-heaters.html\",\"displayText\":\"A.O. Our industry-leading unit heaters are easy to install and accommodate any need. When making a purchase decision based on ratings, keep in mind that models with higher numbers are often deluxe heating units with extra features and benefits. Outdoor Air Reset is optimal in regions with substantial daily temperature swings. Whether natural or LP gas, conversions are simple and quick through a single orice conversion with kits included as a standard feature. The furnace AFUE rating is calculated using the total annual heating output from the furnace versus the amount of fuel input over the same time period. The PTP stainless steel tubular heat exchanger is STANDARD on all units with a 10-year warranty. As the outdoor temperature drops, discharge temperatures increase and vice versa. Installation. When hydrogen is produced from water electrolysis using only power from renewable energy sources, it is known as "green" hydrogen. SterlingHVAC Reznor 175000 BTU Gas Separated Combustion Heater UEZ180 We are a hydronic heating professionals and manufacturer of environmentally friendly and high efficient wall hung boilers, on-demand tankless water heaters, stainless steel indirect hot water heaters, and unit heaters.