Gas Tankless Water Heater Comparison


Compare our models that are powerful enough to power 2 - 3 Showers


Model RTG53 RTG74 GT199
Showers 2 2-3 2-3
BTU's 145,000 199,000 199,000
GPM @ 90° F Rise 2.6 gpm 3.7 gpm 3.7 gpm
GPM @ 80° F rise 3.0 gpm 4.1 gpm 4.1 gpm
GPM @ 70° F rise 3.4 gpm 4.7 gpm 4.7 gpm
GPM @ 60° F rise 3.9 gpm 5.5 gpm 5.5 gpm
GPM @ 50° F rise 4.7 gpm 6.6 gpm 6.6 gpm
GPM @ 45° F rise 5.3 gpm 7.4 gpm 7.4 gpm
Temperature Range 100-140 degrees 100-140 degrees 100-180 degrees
Venting Diameter 3 Inch Stainless 4 Inch Stainless 4 Inch Stainless
Annual Operating Costs $167 NG  $246 LP $167 NG  $246 LP $167 NG  $246 LP
Energy Factor .82 .82 .82
Gas Connection 3/4" NPT 3/4" NPT 3/4" NPT
Water Connection 3/4" NPT 3/4" NPT 3/4" NPT
Water Pressure 14 PSI 14 PSI 14 PSI
Minimum Flow to Activate 0.66 gpm 0.66 gpm 0.66 gpm
Max Hot Water Output 5.3 gpm 7.4 gpm 8.5 gpm @ 35° Rise
Dimensions 20 1/2 H x 13 3/4 W X 5 1/4 D 25 3/4 H x 14 7/8 W x 11 1/8 D 25 3/48 H x 14 7/8 W x 11 1/8 D
Weight 36 lbs 55 lbs 55 lbs
Electrical Supply 120 V, 60 Hz, 2 Amps 120 V, 60 Hz, 2 Amps 120 V, 60 Hz, 2 Amps
Exhaust Venting Horizontal or Vertical Horizontal or Vertical Horizontal or Vertical
Warranty 10 Year Limited Warranty on Heat Exchanger; 3 Years Limited on Parts

10 Year Limited Warranty on Heat Exchanger; 3 Years Limited on Parts

10 Year Limited Warranty on Heat Exchanger; 3 Years Limited on Parts
Comments Ideal for Southern States best seller Heavy Duty Durable Unit Best Selling Commercial Heater


Compare our models that are powerful enough to power 1 - 2 Showers


Model RTG53 RTG42
Showers 2 1
BTU's 145,000 118.000
GPM @ 90° F Rise 2.6 gpm 2.1 gpm
GPM @ 80° F rise 3.0 gpm 2.4 gpm
GPM @ 70° F rise 3.4 gpm 2.7 gpm
GPM @ 60° F rise 3.9 gpm 3.2 gpm
GPM @ 50° F rise 4.7 gpm 3.8 gpm
GPM @ 45° F rise 5.3 gpm 4.2 gpm
Temperature Range 100-140 degrees 100-140 degrees
Venting Diameter 3 Inch Stainless 3 Inch Stainless
Annual Operating Costs $167 NG  $246 LP $165 NG  $244 LP
Energy Factor .82 .83
Gas Connection 3/4" NPT 3/4" NPT
Water Connection 3/4" NPT 3/4" NPT
Water Pressure 14 PSI 14 PSI
Minimum Flow to Activate 0.66 gpm 0.66 gpm
Max Hot Water Output 5.3 gpm 4.2 gpm
Dimensions 20 1/2 H x 13 3/4 W X 5 1/4 D  20 1/2 H x 13 3/4 W x 5 1/4 D
Weight 36 lbs 36 lbs
Electrical Supply 120 V, 60 Hz, 2 Amps 120 V, 60 Hz, 2 Amps
Exhaust Venting Horizontal or Vertical Horizontal or Vertical
Warranty 10 Year Limited Warranty on Heat Exchanger; 3 Years Limited on Parts

10 Year Limited Warranty on Heat Exchanger; 3 Years Limited on Parts

Comments best seller Ideal in Southern States for 1 shower and a sink