Buderus G115WS/5
Buderus G115WS/5
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Buderus G115WS/5 - 136K BTU - 87.0% AFUE - Hot Water Oil Boiler - Chimney or Direct Vent - Burner Sold Separately



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Buderus G115WS/5 - 136K BTU - 87.0% AFUE - Hot Water Oil Boiler - Chimney or Direct Vent - Burner Sold Separately
Buderus G115WS/5 - 136K BTU - 87.0% AFUE - Hot Water Oil Boiler - Chimney or Direct Vent - Burner Sold Separately
Model: G115WS/5
Product Q&A
How-To Articles

Recommended Accessories

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Expert Recommended Accessories Selected by Ken, our Expert
Required Accessories 9
These accessories are required to properly setup/install this product.
Optional Accessories 10


    The Buderus G115WS is an advanced oil boiler capable of impressive efficiencies. The stainless steel burner (sold separately) has the capability to pre-mix fuel and oxygenated air before combustion, resulting in a cleanly burning flame that emits remarkably low emissions. The G115WS has the ability to automatically adjust boiler heat to meet temperature demand using an outdoor reset control, both increasing efficiency and dramatically increasing the life of the boiler. An insulating enclosure and patented flexible cast iron rounds of a boiler package that will last you for years to come.
  • Ideal for New Installations or Renovations
  • The G115WS boiler is ideal for both new construction and renovations of aged housing. Two ETL approved venting options ensure that proper venting can be achieved in old or new construction.
  • Auto Adjusting Boiler Temperature
  • Conventional boilers typically operate at a set temperature at all times. The G115WS, however, changes its internal water temperature to suit outdoor conditions. This dramatically increases efficiencies and boiler life.
  • Included Leveling Legs
  • Included with the G115WS boiler are a set of adjustable legs, allowing the boiler to remain level even on inclined surfaces.
  • Flexible Cast Iron
  • The heat exchanger of the Buderus G115WS boiler is made of patented flexible cast iron, allowing the boiler to resist even the most punishing thermal shock.


specs product image PID-37440
Product Category
General Information
Product Line
Product Category
Medium Learn More
Medium refers to the substance that carries heat through the heating system. Systems are either designed to use either Hot Water or Steam as a medium, and components are usually specific to one or the other.
Hot Water
Heat Exchanger Material
Cast Iron
Fuel Type Learn More
Fuel Type
To create heat, some form of fuel is required. Fuel Type specifies what the product uses as an input to create heat.
Combustion Type Learn More
Combustion Type
Condensing appliances use leftover thermal energy from combustion gases to heat water in a secondary heat exchanger, resulting in higher efficiency and lower exhaust temperature.
Vent Type Learn More
Vent Type
Products that use combustion (burning) of fuel to create heat also create potentially dangerous gasses that need to be exhausted (AKA "Vented"). Depending on the product, venting can be done via a chimney, through a side wall, or use a second vent to provide fresh air to the appliance.
Chimney or Direct Vent
DHW Production Learn More
DHW Production
DHW (Domestic Hot Water) is potable water for uses other than space heat. Some boilers are able to provide DHW "out of the box", while others can do so with the purchase of optional accessories.
Modulating/Staging Learn More
Stages are unique speeds or levels that equipment can operate at. More stages allow for better fine-tuned control of output, which improves comfort and efficiency. Modulating equipment can operate across a range of levels, giving the highest level of fine-tuned control. Learn More
Mount Type
Maximum Altitude
2000 Feet
Assembly Type
Includes Pump
Included with Burner Kit
Burner Model
Sold Separately
AFUE Learn More
AFUE (Annual Fuel Utilization Efficiency) measures the efficiency of combustion equipment over the entire heating season, and is calculated by dividing the amount of energy that is actually heating your home by the total energy contained in the fuel used by the boiler/furnace. Learn More
87 %
Input Rate
1.1 GPH
DOE Heating Capacity Learn More
DOE Heating Capacity
Also referred to as Gross Output, this is the output of a boiler after accounting for combustion efficiency. We recommend sizing hot water boilers based on the DOE Heating Capacity.
136000 BTU
Net I=B=R Capacity Learn More
Net I=B=R Capacity
I=B=R, also referred to as Net Output or AHRI Capacity, is the rated heat output of a boiler after accounting for combustion efficiency, piping loss, and an extra pickup factor. We recommend sizing steam boilers based on the I=B=R rating.
119000 BTU
Electrical Data
120 Volts
60 Hz
Fluid Content
12.9 Gallons
Flue Connection Size
5 Inches
Supply Connection
1 1/4 Inches
Return Connection
1 Inch
Product Height
30 3/8 Inches
Product Width
23 2/3 Inches
Product Depth
33 2/3 Inches
Product Weight
476 Pounds
IBR Listed
Warranty Information
Parts Warranty Learn More
Parts Warranty
A warranty is a safeguard from defects in manufacturing and can vary in length and terms. Some manufacturers require registration for extended warranty benefits, be sure to check out features and the warranty document. To see the manufacturer's warranty statement, click on the Manuals tab. Learn More
1 Year
Heat Exchanger Warranty
Lifetime Years


Buderus G115WS/5 Reviews & Ratings

Product Q&A

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Product Questions Answered by Ken, the eComfort Product Expert
What else would I have to buy to change out my boiler?
from Massachusetts 
August 30, 2016

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Buderus G115WS/5 - 136K BTU - 87.0% AFUE - Hot Water Oil Boiler - Chimney or Direct Vent - Burner Sold Separately
Buderus G115WS/5
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