• Modulating heating operation includes: - Modulating gas valve, inducer and circulating blower - Modulating operation from 100% to 35% input in 100 increments with nearly constant temperature rise. • Easily applied in upflow, horizontal left or right, or downflow installation with minimal conversion necessary. • Compact, easy to install, ideal height 33" tall cabinet. • ECM variable speed drive for cooling SEER enhancement, improved comfort with optional airflow delay profiles, and continuous fan options for IAQ performance. • Easy access to controls to connect power/control wiring. • Built-in, high level self diagnostics with fault code display. • Low unit amp requirement for easy replacement application. • All models are convertable to use propane (LP) gas. • Electronic Hot Surface Ignition saves fuel cost with increased dependability and reliability. • 100% shut off main gas valve for extra safety. • 24V, 40 VA control transformer and blower relay supplied for add-on cooling. • Airflow leakage less than 1% of nominal airflow for duct performance testing conditions. • Solid removable bottom panel allows easy conversion. • Hi-tech tubular aluminized steel primary heat exchanger with stainless steel tube/aluminum fin secondary heat exchanger for outstanding efficiency. • No knockouts to deal with, making installation easier. • Movable duct connector flanges for application flexibility. • Quiet inducer operation, burner, and blower operation. • Inducer rotates for easy conversion of venting options. • Fully supported blower assembly for easy access and removal of blower. • External air filters used for maximum flexibility in meeting customers IAQ needs. • Insulated blower compartment for thermal and acoustic performance. • 1/4 turn knobs provided for easy independent door removal. • Internal condensate trap design (patent pending) provides condensate management options and is self priming to prevent nuisance problems. • These models may be connected as part of a communicating control system using a 4-wire connection bus.