80% Variable Speed, Two-Stage Heating FurnaceEASIER TO SELL 80% AFUE Series 'B' approved for Twinning applications (0902116, 1002122, and 1352422) with accessory (order separately) Supports two-stage cooling units Flame roll-out sensors standard Category I venting Blocked vent switch Dehumidification feature in cooling 24 VAC humidifier terminal Electronic air cleaner terminal California NOx approved TOUGHER Variable speed ECM blower motor Adjustable heating blower OFF delay Factory set blower ON delay RPJ aluminized steel heat exchanger High temperature limit control prevents overheating Direct ignition with Silicon Nitride ignitor One piece prepainted steel cabinet QUIETER Two-stage heating operation Two-stage induced draft blower In-shot burners Insulated blower compartment EASIER TO INSTALL AND SERVICE 33-1/3' (847mm) high, for ease of installation Innovative knobs for easy door removal and secure attachment Factory shipped for natural gas, with propane gas conversion kits available Four position - upflow/downflow/horizontal (left/right) installation Three position vent elbow capability Through the casing flue pipe for counterflow applications Common venting with other Category I appliances Masonry chimney adapter available Self diagnostics Slide out blower assembly WARRANTY * 10 year No Hassle Replacement limited warranty 20 year heat exchanger limited warranty 5 year parts limited warranty With timely registration, an additional 5 year parts limited warranty * For owner occupied, residential applications only. See warranty certificate for complete details and restrictions, including warranty coverage for other applications.