Gas Furnaces
  Signature® Signature® Elite® Elite® Elite® Elite® Merit® Merit®
FEATURE G61V G60V G61 G51 G60 G50 GMH95 GMV95
Energy Efficiency Up to 95.0% AFUE 80% AFUE 94.1% AFUE Up to 92.1% AFUE  80% AFUE 80% AFUE 95% AFUE 95% AFUE
Quiet Operation SilentComfort™ Technology  SilentComfort™ Technology  Fully Insulated Fully Insulated Fully Insulated Fully Insulated    
Variable Speed Motor        
Stages of Heating 2 2 2 1 2 1    
Orientation Multi-Position with no internal changes Up-flow/horizontal or downflow  Multi-Position with no internal changes 4-Way Multi-Position Up-flow/horizontal or down-flow  Up-flow/horizontal or down-flow  Multi-Position Installation Multi-Position Installation
Enhanced Humidity Control            
Ultralow Constant Fan Low speed  Low speed  Low speed  Low speed     
Insulated Blower Compartment    
Ignition SureLight® SureLight® SureLight® SureLight® SureLight® SureLight®    
Parts and Control Warranty 5 year limited warranty on parts and controls  5 year limited warranty on parts and controls  5 year limited warranty on parts and controls  5 year limited warranty on parts and controls 5 year limited warranty on parts and controls 5 year limited warranty on parts and controls 10 year limited warranty on parts and controls 10 year limited warranty on parts and controls
Heat Exchanger Warranty Limited Lifetime Warranty  20 Year Limited Warranty Limited Lifetime Warranty  Limited Lifetime Warranty 20 Year Limited Warranty 20 Year Limited Warranty Limited Lifetime Warranty Limited Lifetime Warranty