Fuel Types

Wood fuel, your options and what’s best for your boiler

Most biomass boilers run on wood chip, wood pellets, logs or briquettes. Others are designed to burn straw and hay bales, waste wood and shavings from manufacturing processes.

Biomass boilers work most efficiently when the appropriate wood fuel is used, in accordance with the manufacturer’s guidelines. If the wood fuel is too wet (or even too dry), extremely irregular in size/shape, or from a low quality crop source, the fuel feed can become obstructed or the boiler can combust the fuel at a much quicker, less efficient, rate.  The best type of wood fuel for your biomass boiler should be discussed with your boiler supplier.

image of pile of wood chipimage of pile of logsimage of pile of wood pellets

You can read more about the benefits of different fuel types, chip and pellets, and which might be best for your project in our blog Wood Chip vs. Wood Pellets - The benefits of different biomass wood fuel.

Research your local fuel supplier
The Biomass Suppliers List (BSL) is a fantastic source of wood fuel providers that you can search through using just a postcode. Businesses and their products on this list meet certain standards, as set out by the UK Timber Standard for Heat and Electricity, which ensure that the wood supplied is in line with RHI-qualifying criteria.  Whether you intend to claim the RHI or not, obtaining your fuel from a reputable and approved supplier is recommended to ensure a constant supply of high quality wood.

Keeping your system running efficiently
Using the best quality wood fuel for your biomass heating system is the most efficient and cost-effective way of fuelling your heating system, whilst minimising possible issues that could arise from using lower-quality fuels.

Most of our Herz boilers offer the flexibility of being able to run on either wood chip or wood pellet fuel. To change between fuel types, a re-commissioning visit is required to align the boiler software with the new fuel features and requirements to ensure a smooth transition.

We also offer Industrial solutions for other types of wood fuel, such as waste, treated and non-woody options, alongside the Domestic and Commercial boiler options.

Criteria for wood fuel for Herz biomass boilers
Although each product type may have some variation possible, Herz biomass boiler products work best with:

Wood pellets according to:
  – EN 14961-2: property class A1
  – Swisspellet, DINplus, ENplus or ÖNORM M7135

Wood chips according to:
  – EN 14961-1/4: property class A1, A2, B1 and particle size P16B, P31,5 or P45A
  – ÖNORM M7133: G30-G50
  – Maximum moisture content 40% / W40