Solid fuel is becoming more popular as a way to heat homes and to contribute towards the water heating load.

Solid fuel appliances come in all shapes and sizes.  The current fashion for wood burners is helping increase the market for this fuel type along with more traditional cooking appliances and the newer pellet burning stoves and boilers.

In order to capture the heat from these appliances it is often the case that they will have some form of heat exchanger and water connections so that water can be circulated, heated and used for space and water heating.

It is not always clearly understood that an appliance which runs at a high temperature can be a low output device but this is often (not always) the case, with contributions of less than 10kWh being produced.  This may be fine for heating water, in fact this sort of output would provide quite reasonable heat up times for hot water tanks and cylinders if or when it is constant.  In itself, though, it can fall short of whole house and hot water heating and this must be borne in mind.

The coupling of this output is usually via the internal coil (heat exchanger) of a traditional open vented cylinder.  Open vented units were and still are usually specified for these duties as they are open to atmosphere with inherently safe discharge arrangements in case of overheat.

What is not as well understood is that these appliances can be linked to mains pressure cylinders, too.  In the installation section on this page you can see some suggested methods of complying with Part G whilst enjoying the benefits of mains pressure.

A thermal store is a useful way of combining energy inputs utilising solid fuel in addition to other inputs to contribute towards heating and hot water, although it is possible to do this for water heating with unvented cylinders.

HWA recommend that in all cases installers should consult with appliance manufacturers and hot water storage supplier to ensure compatibility.

The trend to renewables includes solid fuel and more information can be found within the Renewables section of this site.