Wood Log boilers

Modern log boilers provide clean and efficient heating, whilst utilising one of the most cost effective means of heating. Log boilers are suitable for all domestic-sized situations and for smaller commercial applications, such as country houses and small industrial buildings. They need careful consideration on larger applications where the physical requirement of splitting and loading the fuel can become time consuming.

Nominal output and fuel chamber size

When choosing a log boiler, it is important to consider both its nominal output and fuel chamber size to ensure it is suitability. The nominal output of a boiler is the rate at which the energy stored in the wood is converted to heated water. It is important the nominal output of the boiler is at least matched to the property it is heating so as to ensure it can keep up with the rate at which heat is lost from the property. To ensure the boiler only requires loading and igniting once per day in average winter temperatures, it is important the fuel chamber is sized sufficiently.

Benefits of a log burning boiler;

  • Simple to operate
  • Burns logs and clean waste wood, resulting in very low heating costs
  • Eligible for both the Domestic and Non-Domestic Renewable Heat Incentive Schemes
  • Requires only once or twice a day fuelling (if sized correctly)
  • Lambda controllers ensure high reallife efficiencies up to 93%
  • Wood logs can be stored locally to the boiler house to reduce time and labour
  • The boiler house can be located remotely to the property to be heated
  • Can be easily linked with an alternative heating source
  • Can have automatic ignition
  • Can have on board fuel calculator which advises how much fuel to load into boiler

Electronic combustion control

To burn wood efficiently, there are two stages of combustion to be controlled - the burning of the volatile gases, and the burning of the fixed carbons (charcoal). The release of the wood gases is known as gasification, where the wood is partially burnt in the fuelling chamber and the gas released. The gas is then drawn into a separate combustion chamber where it mixes automatically with secondary air to burn completely in optimum conditions. The control of this two stage burning process requires boilers to incorporate intelligent combustion controllers, known as a Lambda sensor, to achieve the highest possible efficiencies. This sensor is situated in the flue way of the boiler and constantly monitors the flue gases and adjusts the primary and secondary air to ensure the boiler is always working to its maximum possible efficiency.

Log Boilers

The HDG range of log burning boilers are renowned for their outstanding quality and reliability. From the entry level HDG R Series, the latest HDG F Series, the workhorse that is the HDG Euro, or the HDG Turbotec that take can take 1 metre length logs, HDG have the answer.


During the combustion process, more energy will be produced in the form of heated water than is required at the time by the heating system. This excess heated water is therefore transferred and stored into a highly insulated water tank, known as an accumulator. The high levels of insulation of these accumulators mean this energy can be stored for long periods until it is required for heating or hot water.

Options to make life easy

A number of options are available to make life with a log boiler that little bit easier. Automatic ignition systems enable the boiler to be loaded with fuel at a time of day that suits, with the boiler igniting automatically via an electrical ignition fan only when the heating system requires more energy. Fuel loading sensors inform the user of how much fuel to load into the boiler, based upon outside weather temperature and forecasted energy use.