PRO: 175-1,000kW Biomass Boilers

The PRO design offers outputs from 175-1,000kW (250kW from a single unit) and is eligible for the RHI incentive.

Guntamatic: The PRO Range

This range incorporates medium commercial and industrial biomass boilers which offer extremely high efficiency. We are extremely proud to be able to bring this range to customers in your area.

The PRO design offers outputs from 175-1,000kW (250kW from a single unit) and is eligible for the RHI.

Seriously Low Emissions

The PRO's emissions have been measured as significantly below the maximum emissions set out as a requirment 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 PRO 175 Emissions (Wood Chips) 16 87
Guntamatic PRO 250 Emissions (Wood Chips) 16 87
Guntamatic PRO 250.1 Emissions (Wood Chips) 16 88


PRO boilers can burn EN Plus A1 or A2 wood pellets, G30 or G50 wood chips. This biomass boiler model is famed for its high efficiency, maintaining 96% between 26-100% output. With the PRO range, you know you’re getting the most heat possible for your money.


The PRO is fully automated for a quick start with hot air ignition. It also features a lambda probe which allows the right amount of oxygen to enter for optimum combustion, meaning you enjoy optimum efficiency from your biomass boiler.

Easy Control

Supplied as standard, the PRO’s touch screen control panel allows you to change between fuels, view performance information, diagnose faults and even manage settings from your smartphone (with an optional GSM module).

Low Ash Content

The PRO is designed with a levelling auger so that as much ash as possible can be deposited in the 96 litre ash bins. Given that the PRO only generates 0.5-1% ash to the volume of fuel, you’ll only need to empty the ash bins every six to eight weeks.

High Efficiency Combustion

Under controlled combustion conditions, the PRO’s lambda probe delivers enough oxygen and offers maximum efficiency. The large combustion zone can generate temperatures up to 1,200°C, giving you the most amount of heat for your money.


Another innovative feature of the PRO is its modular step grate with vertical turbulators that move up and down to prevent the buildup of deposits and keep your boiler running efficiently

Fire Safety

With its sophisticated ‘burn back’ system, suction fan to create negative pressure in the combustion chamber and an automatic rotary valve, the PRO is one of the safest models on the market. Larger versions of the PRO are designed with temperature controls in the fuel store.

When planning your fuel store, evaluate your likely usage so that you can build a store that’s big enough. Ideally, you shouldn’t need to refill it more than three or four times a year. A range of auger length options support a wide range of custom-built fuel store sizes.

Flex Size Auger Length Options
Flex 1 1,080 – 1,559mm
Flex 1.5 1,560 – 2,039mm
Flex 2 2,040 - 2,519mm
Flex 2.5 2,520 -2,999mm
Flex 3 3,000 – 3,479mm
Flex 3.5 3,480 – 3,959mm
Flex 4 3,960 – 4,439mm
Flex 4.5 4.440 – 4.919mm
Flex 5 4.920 – 5.399mm

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

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 PRO 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 PRO 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

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PRO Technical Data





ENPlus A1 or A2 Wood Pellets
G30 or G50 Wood Chips

Boiler Output        
175kW 175-188 Overall performance from a range of modules
250kW 199-250
Draught Requirement (mBar) 0.1
Boiler Temp. oC 60 - 85
Rtn Flow Temp. oC 55
Water Contents (Ltrs) 600 1,200 1,800 2,400
Operating Pressure (Bar) Max. 3
Ash Storage Vol (Ltrs) 240 480 720 960
Flue Connection Dia (mm) 250 2 x250 3 x 250 4 x 250
Weight (kg) 2,000 4,000 6,000 8,000
Depth (mm) 2,300  
Height (mm) 2,100
Safety Heat Exchanger Yes
Power Supply (V/Amp) 200V/20A



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.

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.