With this type of system, your radiators and water tank are heated by a solid fuel appliance. The main two types of solid fuel appliances are:

Fires

A boiler is fitted behind the fire which heats the hot water and radiators. The smoke and gases produced are sent up the chimney.

Programmer

A programmer can be added to a solid fuel system so it can be set to turn on the heating and hot water at a time you want.  However, the fire needs to be burning when it comes on.

Hot water

With a solid fuel system the hot water heats the whole time the fire is lit. The hot water cylinder is usually found in the kitchen or the attic and is heated by the fire and the boiler by a gravity circuit. 

As the water is being heated constantly when the fire is burning the water can overheat so it important to stop this before the water boils. A device called a high-limit thermostat stops this from happening. It is fitted either on the hot water cylinder or on the pipe going into the cylinder and is set at around 70°C. Once the water in the cylinder or in the pipe reaches this temperature the high limit thermostat starts the central heating pump and sends water through the radiators. Once the temperature drops below 70°C it switches the pump off again. This cycle can be repeated often and unfortunately it will still do this in the summer months. However, this is the only way to stop the water from overheating.

Radiators and Thermostatic Radiator Valves (TRVs)

Radiators for this system are similar to Electric and Gas Wet Central heating systems which have water in them. The water moves around the radiators and is heated by the boiler.

TRVs are controls that are attached to each radiator so that you can turn the heat up or down in that room, 1 being cold 5 being hot. Keep low in the rooms you do not use often. You can also set them to 0 to turn the radiator off completely.

Types of fuel

You need to buy solid fuels to power the system. These vary largely in price and quality. The quality of fuel can greatly affect how well the heating system works. The main types of fuel are:

Coal

Coal is efficient however it can be expensive.  It can also vary in ash and volatile gas content which can reduce how much heat it gives out.

Smokeless fuels

Smokeless fuels can be manufactured or natural. They are more efficient than coal. Smokeless fuels are perfect for closed appliances as they release heat over a longer period.

Quality and price

Better quality fuel is more expensive to buy however the results are far better. Cheaper fuels will generate less heat and the temperature of hot water and the radiators will be much lower. Cheap fuel also has a higher ash and soot content so the chimney will need to be swept and the ashes emptied more often.

Tips on getting the best from your solid fuel system

• Buy better quality fuels.

• Always fill the firebox to its maximum capacity. The fuel should be filled to the level of the front firebars and sloped back up towards the boiler.

• Once you have lit a fire it is best to wait until the hot water cylinder is fully heated before turning on the central heating.

• Never run the central pump with the fire in a low setting or with the firebox partly filled. This will circulate lukewarm water through the radiators and could cause condensation in the boiler which results in corrosion.

• Remove the ash morning and night.

• Check and clean the throat plate regularly.

• Sweep the chimney regularly - three times per year for appliances burning coal and wood or once per year for appliances burning a good smokeless fuel.