Weil Mclain 383500703

383-500-703 Ultra 155 Natural Gas Ultra Efficient Condensing Gas Boiler

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Weil Mclain Products
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Weil Mclain 383500703

Weil Mclain 383-500-703 Ultra 155 Natural Gas Ultra Efficient Condensing Gas Boiler
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MSRP: $5,507.00
Shipping: FREE
Today's Price: $4,249.00
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SKU: 383500703
Condition:Brand New Factory Sealed With 1 Year USA Warranty
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Weil Mclain Products
Quick Specs:
Brand: Weil Mclain
SKU: 383500703
UPC: 672619185944
Stock Id: SID229514
Fuel Type: Propane/Natural Gas
Width: 22-5/8"
Height: 41-1/8"
Depth: 19"
Energy Star: No
Technical Details
Application: Heating
System Type: Hydronic (water)
BTU Output: 123000
BTU Input: 155000
Vent Size: 3"
Water Connection: 1"
Gas Connection: 1/2"
Boiler Type: High Efficiency

Weil McLain Ultra UG-155-S3-UE, Natural Gas Series 3 High Efficiency Condensing Hot Water Residential boilers feature AFUE efficiency up to 95.6% . These are some of the highest efficiencies in the industry, however, Ultra Series boilers, when used in common low temperature applications have annual efficiencies of 98.0%. Besides being Ultra High Efficient, the Ultra boiler is environmentally friendly.


  • Cast Aluminum Mono Block - aluminum provides 10 times better and faster heat transfer than stainless steel
  • Variable Speed Blower Assembly - constantly matches combustion output to your heating needs
  • Control Panel with Digital Display - u-Control user's Interface Module is provided to display system operating status and fully adjustable parameter values as well as diagnostic codes for easy troubleshooting and optimum system performance
  • Venture Mixing System with Air Silencer - precisely mixes air and gas providing higher efficiency and quiet operation
  • Made in the USA
  • Stainless Steel Burner with woven steel fiber mesh
  • Outdoor temperature sensor
  • Direct Spark Ignition
  • Automatic air vent
  • Pressure gauge
  • Condensate drain assembly
  • NTC temperature sensors on the boiler supply/return and flue
  • 120V Power switch
  • Low water protection
  • Domestic hot water priority
  • High temperature limit protection
  • Boiler freeze protection
  • Factory tested


  • Fuel Type: Propane/Natural Gas
  • System Type: Hydronic (Water)
  • Vent Size: 3"
  • Water Connection: 1"
  • Gas Connection: 1/2"
  • BTU Input: 155000
  • BTU Output: 123000
  • Boiler Type: High Efficiency
  • Width: 22-5/8"
  • Height: 41-1/8"
  • Application: Heating
  • Depth: 19"
  • Vent Type: ABS

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