Sustainable Hotel
Environmental Management
Additional Information
Benchmarking Tool
Solar Thermal Heating
Solar Photovoltaic Cells
Wind Turbines
Combined Heat & Power
Ground Source Heat Pumps
Wood Boiler & Hydro
Rainwater Harvesting
Control Systems
Financial Assistance
Environmental Reviews
Waste Audits
boiler picture

The following general principles apply to managing gas boilers:

- Boilers should be serviced annually with a Corgi registered contractor.

- Old boilers should be replaced with modern condenser boilers rated A for energy efficiency. They are over 90% efficient compared to 60% for older boilers.

- Boilers should be controlled by digital timer in order to limit the periods during the day when the boiler is fired and therefore save energy.

- ‘Dry cycling’ is prevented where the boiler is still burning when the required temperature for hot water or heating has been reached during ‘timer on’ periods, by correctly wiring the boiler thermostat into the timer control.

- Boiler Step Control: Have multiple boilers controlled so that they fire sequentially depending on demand, rather than always firing all boilers all the time. Therefore when the heat demand is low, only one of the boilers will be fired, but this one would be operating under full load and therefore running efficiently. Boilers are most efficient when operating at their full output rating.

- For a large building it may be beneficial to split the heating into zones, for example each floor or area could be a separate zone. Then heating can be limited to occupied zones rather than heating the whole building by having a separate boiler for each floor, or by the use of system switches.

- Use central or zoned thermostats to control temperature in each area.


Check the energy efficiency of the boilers regularly. Action Energy (Tel: 0800 585794, provides an excellent free energy audit service that could be utilised to check adjustment of the boiler’s temperature setting and efficiency.

Hot water: Cylinders should be lagged with a minimum of 80mm insulation to retain heat. Set temperature of hot water cylinders to 60°C, which ensures that it is hot enough to combat the risk of Legionnaires disease, but not too hot to be energy wasteful.

Thermostatic Radiator Valves (TRV’s) should be installed on all radiators because they allow the temperature to be controlled in zones within the building, according to requirement. Unoccupied rooms or areas that require less heat can have the temperature turned down or switched off. This reduces the flow of hot water and reduces the demand on the boiler.

A useful tip is to ensure radiators aren't obstructed by furniture and don't set thermostats too high; costs rise by 8% for every 1°C increase above 19°C.

Heating and Hot Water