Powerchip: 20-100kW Biomass Boilers

The Guntamatic Powerchip burns wood chips, wood pellets, grain or miscanthus.

Guntamatic: The Powerchip Range

Powerchip boilers have outputs from 20-400kW (up to 100kW from a single unit). We often use a cascade approach, installing two or more boilers in the same system to achieve outputs up to 400kW. This kind of flexibility allows us to install the most efficient system in modulation.

This range is, where necessary, MCS accredited and all models are RHI compliant.

Seriously Low Emissions

The Powerchip's emissions have been measured as significantly below the maximum emissions set out as a requirement for the RHI. The values of each model are in the table below and you can see the certificate here.

Boiler PM NOx

Maximum Emissions

30 g/GJ 150 g/GJ
Guntamatic Powerchip 20/30 Emissions 8 88
Guntamatic Powerchip 50 Emissions 11 96
Guntamatic Powerchip 75 Emissions 11 99
Guntamatic Powerchip 100 Emissions 10 102
Guntamatic Powerchip 101 Emissions 10 102


Guntamatic’s Powerchip boilers are famed for their ability to maintain 96% efficiency between 26-100% of output. So you’ll enjoy maximum value for money through a more complete burn.


Powerchip boilers can burn ENPlus A1 or A2 wood pellets, G30 or G50 wood chips, grain or Miscanthus. There are a range of fuel storage options, from converted buildings to custom-built structures, into which your fuel can be directly loaded.

Fully Automated

These boilers are designed to achieve a quick and easy start with automatic hot air ignition and a lambda probe to add just the right amount of oxygen. The result is optimum combustion and optimum efficiency.


The Powerchip features Guntamatic’s innovative self-cleaning system, where turbulators move constantly to keep heat exchanger tubes from buildup of efficiency-reducing deposits.

Control Panel

Your Powerchip boiler comes with a touch screen panel fitted as standard which allows you to quickly and easily change between fuel types.

This puts you in control and gives access to efficiency, fault and maintenance information. Plus, if you opt for the additional GSM module, you’ll be able to control the boiler’s settings from your smartphone.

Low Ash Content

For the volume of fuel, just 0.5-1% ash is generated, meaning that you’ll only need to empty the vast up to 80 litre ash bin every six to eight weeks.

Variety of Wood Chip Delivery and Storage Options

An up to 7m single auger length auger and a 5m agitator means that Powerchip can support a range of fuel store and delivery options.

Some common designs are highlighted below;

50 Years’ Experience Built In

Having recently hit their 50-year anniversary, it’s clear that Guntamatic are market leaders in renewable energy technology. Experience means that every boiler they make is created with huge industry expertise, and the Powerchip is no exception.

Parts Available for 20 Years

Guntamatic are unique amongst biomass boiler manufacturers as they make all of their own structural components.

Every single part of the Powerchip is of the highest standards, offering you maximum return on your investment, low maintenance requirements and a long service life. You can get hold of spare parts easily as Guntamatic guarantees to make parts available for 20 years.

European Training Academy

They put an equal amount of effort into developing installers at their European Training Academy, so an authorised, highly trained and experienced engineer will fit the system for you.

System Dimensions

Guntamatic Powerchip boiler dimensions

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Powerchip Technical Data 20/30 40/50 75 100
  • 6mm Wood Pellets (ENPlus A1 or A2)
  • G30 or G50 Wood Chips
  • ONORM 7139 Quality Grain
  • Chopped Miscanthus, below 25% moisture
Min-Max Outputs        
Wood chips kW 7-30 12-50 22-75 22-100
Wood pellets kW 7-30 12-50 22-75 22-100
Grain kW 7-25 12-25 21-70 (with additive)
Miscanthus kW 7-25 12-25 21-70 (with additive)
Draught Req. (mBar) 0.15 0.20
Boiler Temp. (oC) 60-80 (70 grain) 50-80 (70 grain) 50-80 (70-80 grain) 60-80 (70-80 grain)
Return Flow Temp. (oC) >40 (55 grain) >40 (55 grain) >40 (55 grain) >40 (55 grain)
Elevation of Rtn. Flow Pump (RA60 When Buffered) Pump (Return temperature boost when buffered)
Water Contents (Ltr) 128 147 256 256
Operating Pressure (Bar) Max 3
Grate Ash Storage Vol. (Ltr) 60 60 80 80
Heat Exchanger Ash Storage Vol. (Ltr) 12
Width (mm) 1,574 1,575 1,875
Depth (mm) 950 980 980
Height (mm) 1,670 1,670 1,875
Flue Connection Dia. (mm) 150 180
Weight, no feed auger (kg) 550 585 865 865
Feed Auger Weight (kg) 75 75 75 75
Safety Heat Exchanger Yes
Power Supply 400V/ 16A



Wood Chips

What are wood chips?

Passing small logs or wood waste through a chipping machine produces 3mm pieces (also known as G30). Find out more here.

What is the calorific value of wood chips?

Approximately 3.5 kWh per kg, depending on the moisture content of the chips. We recommend a maximum of 30% moisture and you can check this with a moisture meter.

How much space do I need to store them?

Wood chips need approximately three times as much storage space as wood pellets;

  • Wood Chips = 250KG/m3
  • Wood Pellets = 650KG/m3
Where is the nearest supplier of wood chips?

We always recommend using the fantastic Biomass Suppliers’ List (BSL) for a comprehensive list of high quality suppliers across the UK.

What is the cost wood chips?

If you get bought-in wood chips, you can expect to pay £120 per tonne. Alternatively, if you have your own wood supply, you can arrange for contract chipping for around £50 a time. Contract chippers charge about £150 per hour and they can chip around 15 tonnes in an hour. So you can potentially chip your entire annual supply in half a day and load it straight into your fuel store.

Wood Pellets

What are wood pellets?

Wood pellets are made from compacted sawdust or any other waste produced from sawmills and other manufacturers.

What is the calorific value of wood pellets?

It’s 4.8kWh per kg, meaning you only need one third of the storage space that you would need for chips. Plus you get three times as much heat.

  • Wood Chips = 250KG/m3
  • Wood Pellets = 650KG/m3
How much do I need, compared to oil?

1 litre of oil is equivalent to 2kg of wood pellets.

What is the cost of wood pellets?

You can expect to pay between £180 - £220 per tonne.

Where is the nearest supplier of wood pellets?

We always recommend using the fantastic Biomass Suppliers’ List (BSL) for a comprehensive list of high quality suppliers across the UK.

Can I use any kind of pellets?

The pellets will need to be ENPlus A1 or A2. These are 10-12mm long and 6mm in diameter. Your wood pellets need to be dry, clean, mechanically robust and possess an ash content defined by appropriate standards. They need to be able to flow freely and delivered via a pneumatic system. Check out this handbook from HETAS for more information about wood pellets.


Really? I can burn grain?

Absolutely. Grain is an economical and convenient fuel for biomass boilers. Pourable options like oats, barley and wheat have a low nitrogen content and can be used in models such as Guntamatic’s Powerchip and Powercorn boilers.

What is the calorific value of grain?

It really depends on the grain: barley gives 4.3-4.4 kWh per kg and wheat gives 4.5-4.6 kWh per kg. Grain is slightly denser than Miscanthus, so will need less storage space.

Won't I get clinker?

We advise adding around 0.3 – 0.5% by weight of slaked lime (calcium hydroxide Ca(OH)2) to your fuel before using it in boilers with ratings up to 50 kW and 0.5 – 0.8% for boilers with ratings over 50 kW. This increases the calcium content of your fuel and raises the ash fusion point. This reduces the amount of clinker that can form.

How dry should it be?

Keep moisture content less than 13% to avoid wasting energy on burning off excess moisture. This will ensure your boiler is as efficient as possible.


What is miscanthus?

Also known as ‘elephant grass’, Miscanthus is a perennial grass which grows and spreads quickly, even on land of poor quality. It’s so easy to cultivate and requires little to no intervention. This is why it’s such a popular option for biofuel.

What is the calorific value of miscanthus?

Miscanthus has a calorific value of 3.6-4 kWh per kilogram and weighs 70-90 kilograms per metre cubed. It’s less dense than grain and therefore you’ll need more storage space.

Which boilers will burn miscanthus?

The Guntamatic Powercorn and Powerchip models will both burn Miscanthus (in chopped or pelleted form). To ask about other models, please get in touch.

What moisture content should miscanthus be in order for it to burn?

It’s imperative that Miscanthus is kept dry and ventilated to get the best out of it. Its moisture content cannot be above 20% and it must conform to W20 standards for chopped, air-dried Miscanthus and W30 for storing and drying.

We advise adding around 0.3 – 0.5% by weight of slaked lime (calcium hydroxide Ca(OH)2) to your fuel before using it in boilers with ratings up to 50 kW and 0.5 – 0.8% for boilers with ratings over 50 kW. This increases the calcium content of your fuel and raises the ash fusion point. This reduces the amount of clinker that can form.