Friday, December 8, 2023

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued



The FlexFuel does not meet EPA and is to be sold for commercial purposes only.

Save money and heat your whole home without using fuel oil, propane, natural gas, or electric energy with WoodMaster's Flex Fuel Series. Choose the least expensive fuel: cordwood, wood chips or wood pellets - and burn less of it; guaranteed.

  • Description
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"The Flex Fuel Biomass Boiler by WoodMaster is the American answer to European Multi Fuel Gasification boilers with Lambda Technology.  What is Lambda Technology, you ask?  It is computerized combustion.  Your car uses it to burn cleanly; it is all about combustion and burning cleanly by monitoring the exhaust and regulating the way the fuel is burning by controlling the amount of air that is entering the combustion chamber.  You need three things to make fire: (fuel, heat and oxygen) and how those three things are combined is what determines how clean the burn will be.

Built in Red Lake MN by WoodMaster under license from the leader in European Gasification Boilers, Solar Focus in Austria, the Flex Fuel Biomass Furnace is one of the most advanced solid fuel boilers in the world in terms of efficiency, as well as particulate emissions and environmental impact.  With one of the lowest emissions outputs of any other boiler on the market today, why would you want to purchase an import boiler when there is an alternative made right here in North America?  Replacement parts, local dealers and tech support are all readily available right here, right now.

Flex Fuel is just as the name implies; "Flex-ible", which means it is able to burn Cordwood, or Pellets,  The Flex Fuel burns these fuels so well that WoodMaster makes this Guarantee: if you can find a better burning, more efficient, multi-fuel, gasification boiler anywhere in the world; they will give you your money back; that is called confidence."


  • Fuel Options: cordwood, or wood pellets
  • Lambda sensor analyzes levels in the stack and sends it to the eco manager
  • Variable speed fan adjusts the air intake to reach the optimal burn for efficiency, emissions and prolonged product life
  • Eco manager pulls the system together—from the lambda sensor to the draft inducer—enabling user-friendly maintenance
  • Optional self-ignition is programmable by time or water temperature
  • Self-cleaning heat exchangers assist in maintaining money-saving efficiency levels—with less maintenance
  • Wood gasification technology provides excellent combustion at high temperatures for better efficiency and fewer emissions
  • Large ash chamber makes ash cleanup quick and easy
  • Smoke extraction directs remaining smoke to the flue when you open the loading doors
  • Easily converts from one fuel to another once installed. This gives you more options with less time
  • Solar capable which is another option to save even more money and use less fuel


Click here for Single Line PEX Pipe

Click here for Dual Line PEX Pipe



Specifications Flex Fuel 30 kW Flex Fuel 60 kW
Fire box 22.5" L x 14" W x 25" H 26.5" L x 22" W x 28" H
Fuel door size 13.5" W x 9.5" H reversible with built-in smoke bypass 21.5" W x 10" H reversible with built-in smoke bypass
Construction Heavy duty mild steel Heavy duty mild steel
Draft Fan-induced down draft Fan-induced down draft
Overall size 24" W x 48" L x 54" H 32.5" W x 60" L x 60" H
Capacity 24 gallons 50 gallons
Btu 100,000 200,000
Warranty 10 years 10 years
Shipping weight 1400 lbs. 1800 lbs.
Fuel Cordwood, wood pellets Cordwood, wood pellets

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

WoodMaster Flex Fuel Wood/Pellet Commercial Boiler - Commercial Use Only - Discontinued

Please call or email for a price quote and specify the model you are interested in and your zip code.  One of our sales associates will be glad to get back to you.


Be sure to check out our newly improved Cookstove Community website; the best place online to connect with other cookstove users over stoves, self-sufficient living, alternative energy, and more! Take a look at our selection of videos, articles, and photos, and be sure to visit the forums to connect with like-minded folks from all over.

If you are planning to cook with a cookstove, you will need to understand some basic fire safety. Remember, extinguishing a grease or oil fire with water is not a good idea.

For help choosing and installing a wood boiler, see the links and posts below.

  • Installations
  • WoodMaster Flex Fuel & Ultra Pellet Boiler, Renovator Pellet System, Force Pellet Furnace


    Flex Fuel Review
    January 10, 2016
    Reviewer: Bill Walter
    At night I make a fire in the boiler and reload it once if the
    >> temperature is low or if it was not a sunny day.
    >> The two days in the chart were both sunny days.
    >> Basically the wood burning each night will raise the temperatures in
    >> 880 gallons of storage from 120 degrees to near 160 degrees.
    >> On a cold night, that will take one fire started around 5 pm (after
    >> sun goes
    >> down) and a reload after dinner around 8 pm.
    >> That will get me through the evening and night and the tanks
    >> temperatures can fall back below 120 on a cold night (below 0).
    >> My normal heating system kicks in when the tanks are below 120.
    >> The solar side on a sunny day can raise the tanks temperature some
    >> while keeping up with the heating requirement during the day.
    >> The two heating sources are the wood burning tanks and the solar tanks.
    >> The wood burning tanks are heated by the Flex Fuel which controls the
    >> process.
    >> The solar tanks are heated by the solar panels and the pumps are
    >> controlled by an iSolar Plus controller.
    >> The two heating sources supply the two hot water storage areas,
    >> Radiant and DHW.
    >> This process is controlled by an iSolar BX controller and pumps water
    >> from either the Wood or Solar tanks to either the Radiant or DHW
    >> storage when the temperature differential is over 8 degrees.
    >> The Radiant storage heats the glycol for the in-floor heat in a 3000
    >> sq.
    >> ft. addition and is controlled by the iSolar Plus controller.
    >> The DHW storage provide hot water to the 4000 sq. ft. main house and
    >> also heats the glycol which is inserted into the main house boiler
    >> system.
    >> The extra water storage dumps are necessary because the solar system
    >> by itself can only heat 460 gallons while the wood burning system can
    >> easily heat 800 gallons or more.
    >> Heated water is diverted through the storage dumps when the water
    >> temperature is over 138 degrees.
    >> That helps lower the water temperature returning to the wood burning
    >> tanks and helps keep a high delta between the supply and return from
    >> the Flex Fuel so it does not go into part load.
    >> Piping the Flex Fuel required a learning curve.
    >> I did not have room for a large water storage tank and originally I
    >> was not running the Flex Fuel water through enough indirect storage
    >> to remove the heat fast enough.
    >> Also, since the Flex Fuel is located in a shed outside the house, I
    >> did not want to connect it directly to large capacity storage in case
    >> of freezing issues.
    >> Those problems are solved and the system seems to be running very
    >> effectively.
    >> As far as ease of use goes, it takes me 5 minutes at most to start a
    >> fire and load the wood.
    >> It take about 1 minute to reload it 3 hours later.
    >> I am incredibly satisfied with the way it heats the water and seems
    >> to do every thing pretty automatically.
    >> I originally did test the unit with the pellets and automatic feed
    >> and it worked fine.
    >> But for now, I have years worth of old lumber and pinion pine to
    >> burn, so I have not used the pellet side.
    >> Designing the system and implementing it was a fun project for me and
    >> I am quite happy with the results.
    >> For anyone who has the wood and is fine getting their hands dirty
    >> every once in a while, I would definitely recommend the Flex Fuel.
    >> I would also imagine that there are not many products out there which
    >> are as efficient with how much heat they get out of so little wood.

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