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Weil-McLain Ultra Series 3-UE Gas Boiler - UG-399

Abt Model: ULTRA399
 Discontinued Product This item is no longer available from our website.
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Energy Star Qualified
Gas Fired Water Boiler With Cast Aluminum Heat Exchanger/ Venturi Mixing Body/ Designed To Operate In Low Temperature Condensing Applications/ Outdoor Reset And Domestic Hot Water Priority Standard/ Negative Regulated Gas Valve/ Modulates With 5 To 1 Turn-Down Ratio Capability/ Variable Speed Motor/ High Grade Stainless Steel Burner/ 399 A.G.A. Input (MBH)/ 365 DOE Heating Capacity (MBH)/ 91.7 Percent Annual Fuel Utilization Efficiency (AFUE)/ Bisque Finish
Discontinued (details)

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Product Details

Energy Star Rated - Yes

Weil-McLain Ultra Series 3-UE Gas Boiler, Model ULTRA399


  • Gas fired water boiler with cast aluminum heat exchanger
  • Venturi mixing body mixes air and gas providing higher efficiency
  • Designed to operate in low temperature condensing applications
  • Outdoor reset and domestic hot water priority standard
  • Negative regulated gas valve precisely delivers gas to the boiler
  • U-Control gives you the power for easy set-up and maintenance
  • Modulates with 5 to 1 turn-down ratio capability
  • Variable speed motor matches combustion output to heating needs
  • High grade stainless steel burner features quiet operation, high efficiency, and cleaner combustion for low NOx applications


  • A.G.A. Input (MBH): 399
  • DOE Heating Capacity (MBH): 365
  • Net I=B=R Ratings (MBH): 317
  • Min. Vent Size: 4in. PVC/CPVC
  • Annual Fuel Utilization Efficiency (AFUE): 91.7%

Approximate Weight:

  • Shipping: 297 lbs

Warranty Information:

  • Manufacturer Warranty (authorized online retailer): 5 Years Parts and Labor
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More reasons to buy the Weil-McLain UG-399 from Abt Electronics
  • is an authorized dealer (Learn More).
  • The Weil-McLain UG-399 is Brand New.
  • The Weil-McLain UG-399 Ships in a Factory Sealed Box.
Fuel TypeGas
Gallon Capacity (cu.ft.)2.1
Height (inches)47.75"
Energy Star QualifiedNo
Weil-McLain Ultra Series 3-UE Gas Boiler

Weil-McLain Ultra Series 3-UE Gas Boiler


Delivery is subject to reasonable access to the area without damaging the purchaser's property or the product, or jeopardizing the safety of the delivery personnel.

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