ProLine XE High Efficiency Ultra-Low NOx Flue Damper 40-Gallon Gas Water Heater

The ProLine® XE High Efficiency Flue Damper gas water heater offers highly optimized performance and increased efficiency thanks its automatic flue damper and electronic gas control.

Featuring a 40-gallon (nominal) tank and a 40,000 BTU gas burner, the GUF-40 standard vent delivers a first hour rating of 70 gallons and a recovery rate of 42 gallons per hour. With an 0.65 Uniform Energy Factor, this water heater is ENERGY STAR® qualified. It carries a 6-year limited warranty, and meets Ultra-Low NOx emission requirements.

Categories: ,


  • Electronic Gas Control
  • Intelligent control logic provides enhanced operating parameters and tighter differentials for precise sensing and faster heating response to optimize performance.
  • Diagnostics
  • The electronic gas control incorporates an LED status indicator that monitors system operation and service diagnostics.
  • CoreGard™ Anode Rod
  • A. O. Smith’s anode rods have a stainless steel core that extends the life of the anode rod allowing superior tank protection far longer than standard anode rods.
  • Brass Drain Valve
  • • Solid brass, tamper resistant, enhanced-flow, ball type, valve.
  • • Uses a standard female hose fitting that allows for fast and easy draining during maintenance.
  • • Screwdriver slot features a 1/4 turn radius, for straight-through water flow and a quick and positive shut off.
  • Tech Specs
  • Nominal Capacity: ? 40
  • Rated Storage Volume ? 38
  • UEF 0.65
  • Maximum BTUs: 40,000
  • Power Source: Natural Gas
  • Limited Tank Warranty: 6 Years
  • Limited Parts Warranty: 6 Years
  • Anode: Coregard™ Magnesium Anode
  • T&P Relief Valve: Yes
  • Ignition Type: Electronic
  • Water Connection Location: Top
  • Water Connection Size: 3/4"
  • Emissions: Ultra-Low NOx
  • LEED Rating: 1
  • ENERGY STAR® Certified: Yes
  • FVIR Certified: Yes
  • First Hour Rating: 68
  • Dimensions & Venting
  • Type: Tall
  • Height: 58 1/4"
  • Height w/Draft Hood: 64 1/4"
  • Diameter: 20"
  • Width: 20"
  • Depth: 20"
  • Vent Type: Standard Vent